opinion: Mr. Justice Douglas
  delivered the opinion of the Court. ,
  This is a companion case to Labor Board v. Duval Jewelry Co., ante, p. 1, decided this day. While the latter was a representation proceeding under the National Labor Relations Act, the present case is an unfair labor practice proceeding. It was commenced on the issuance of a complaint charging violations of § 8 of the Act, 61 Stat. 136, 140, 29 U. S. C. § 158, both by petitioner-employer and by petitioner-union. Subpoenas duces tecum and ad testificandum were issued by the Regional Director under the seal of the Board and the facsimile signature of a member. On the day of the hearing petitioners all moved that the subpoenas be revoked. One ground was that they had not been properly issued. Another was that they were issued at the request of the General Counsel of the Board who, it was alleged, was not a “party” to the proceeding within the meaning of the Act. The motions, which were addressed to the Board, were referred to the trial examiner over objection of petitioners. He denied them. Petitioners refused to appear in response to the subpoenas; and the hearing was continued until they could be enforced. Thereafter the present suit was instituted in the District Court for their enforcement. The District Court denied enforcement on the authority of Labor Board v. Pesante, 119 F. Supp. 444. The Court of Appeals reversed. 249 F. 2d 832. The case is here on a writ of certiorari. 355 U. S. 929.
  1. Delegation of authority over the revocation of subpoenas. — The express authority of the Board to revoke extends only to subpoenas “requiring the production of any evidence,” not to subpoenas requiring the attendance and testimony of witnesses. So the argument that Congress has disallowed delegation extends only to the subpoenas duces tecum. What we have said in Labor Board v. Duval Jewelry Co., supra, disposes of the argument that the Board has no authority to delegate to a trial examiner the power to rule on motions to revoke those subpoenas reserving to itself the final decision in the matter. The provisions of those Rules being substantially the same in this type of case as in the représentation cases, the results in the two cases should be the same. We therefore find it unnecessary to consider the argument pressed on us that § 7 (b) of the Administrative Procedure Act, 60 Stat. 237, 241, 5 TJ. S. C. § 1006, grants a power withheld by the National Labor Relations Act. The power to make the revocation procedure applicable to subpoenas ad testificandum seems clear from the authority of the Board contained in § 6 of the Act “to make . . . such rules and regulations as may be necessary to carry out the provisions of this Act.”
  2. Issuance of subpoenas by the Regional Director.— The Act makes clear that the issuance of subpoenas is mandatory. “The Board, or any member thereof, shall upon application of any party . . . forthwith issue . . . subpenas . . . .” The only function remaining is ministerial. Consequently the Board supplies blank subpoenas bearing its seal and the facsimile signature of a Board member to its regional offices and trial examiners. Upon application of a proper party the subordinate official automatically issues the subpoena to the applicant. There is here involved no delegation of any act entailing the exercise of discretion, as in Cudahy Packing Co. v. Holland, 315 U. S. 357. The agents issuing the subpoenas perform ministerial acts only. We cannot read the Act to mean that these burdensome details should be performed by Board members in faraway Washington, D. C. The command of the Act is to issue the subpoena “forthwith” on “application of any party.” Identification of the party hardly rises to the dignity of the discretionary act which is confided solely to the agency heads. This has been the consistent view of the law in the lower courts; and we think it is the correct one.
  3. The General Counsel of the Board as a “party.”— The Act does not define the term “party”; but it does make clear that the role of the General Counsel is a major one. By § 3 (d) of the Act he is given “final authority” respecting the investigation of charges, the issuance of complaints, and the prosecution of complaints before the Board. The General Counsel is, indeed, indispensable to the prosecution of the case. He vindicates the public interest, performing functions previously performed by the Board itself. See National Licorice Co. v. Labor Board, 309 U. S. 350, 352. Plainly the issuance of subpoenas may often be essential to the performance of that role. To relegate him to a lesser role than that of a “party” is to overlook the critical role he performs in enforcement of the Act.
  Affirmed.
  Section 11 (1) of the Act provides:
  “For the purpose of all hearings and investigations, which, in the opinion of the Board, are necessary and proper for the exercise of the powers vested in it by section 9 and section 10—
  “(1) The Board, or its duly authorized agents or agencies, shall at all reasonable times have access to, for the purpose of examination, and the right to copy any evidence of any person being investigated or proceeded against that relates to any matter under investigation or in question. The Board, or any member thereof, shall upon application of any party to such proceedings, forthwith issue to such party subpenas requiring the attendance and testimony of witnesses or the production of any evidence in such proceeding or investigation requested in such application. Within five days after the service of a subpena on any person requiring the production of any evidence in his possession or under his control, such person may petition the Board to revoke, and the Board shall revoke, such subpena if in its opinion the evidence whose production is required does not relate to any matter under investigation, or any matter in question in such proceedings, or if in its opinion such subpena does not describe with sufficient particularity the evidence whose production is required. Any member of the Board, or any agent or agency designated by the Board for such purposes, may administer oaths and affirmations, examine witnesses, and receive evidence. Such attendance of witnesses and the production of such evidence may be required from any place in the United States or any Territory or possession thereof, at any designated place of hearing.”
  See § 11 (1), supra, note 1.
  Section 102.31 (b) of the Board’s Rules and Regulations, 29 CFR, 1958 Cum. Pocket Supp., provides:
  “Any person subpenaed, if he does not intend to comply with the subpena, shall, within 5 days after the date of service of the subpena upon him, petition in writing to revoke the subpena. All petitions to revoke subpenas shall be served upon the party at whose request the subpena was issued. Such petition to revoke, if made prior to the hearing, shall be filed with the regional director and the regional director shall refer the petition to the trial examiner or the Board for ruling. Petitions to revoke subpenas filed during the hearing shall be filed with the trial examiner. Notice of the filing of petitions to revoke shall be promptly given by the regional director or the trial examiner, as the case may be, to the party at whose request the subpena was issued. The trial examiner or the Board, as the case may be, shall revoke the subpena if in its opinion the evidence whose production is required does not relate to any matter under investigation or in question in the proceedings or the subpena does not describe with sufficient particularity the evidence whose production is required. The trial examiner or the Board, as the case may be, shall make a simple statement of procedural or other grounds for the ruling on the petition to revoke. The petition to revoke, any answer filed thereto, and any ruling thereon, shall not become part of the official record except upon the request of the party aggrieved by the ruling.”
  Section 102.26 of the Rules provides:
  “All motions, rulings, and orders shall become part of the record, except that rulings on motions to revoke subpenas shall become a part of the record only upon the request of the party aggrieved thereby, as provided in § 102.31. Unless expressly authorized by the rules and regulations, rulings by the regional director and by the trial examiner on motions, by the trial examiner on objections, and orders in connection therewith, shall not be appealed directly to the Board except by special permission of the Board, but shall be considered by the Board in reviewing the record, if exception to the ruling or order is included in the statement of exceptions filed with the Board, pursuant to § 102.46. Requests to the Board for special permission to appeal from such rulings of the regional director or the trial examiner shall be filed promptly, in writing, and shall briefly state the grounds relied on. The moving party shall immediately serve a copy thereof on each other party.”
  Section 7 (b) provides:
  “In hearings which section 4 or 5 requires to be conducted pursuant to this section—
  “Officers presiding at hearings shall have authority, subject to the published rules of the agency and within its powers, to (1) administer oaths and affirmations, (2) issue subpenas authorized by law, (3) rule upon offers of proof and receive relevant evidence, (4) take or cause depositions to be taken whenever the ends of justice would be served thereby, (5) regulate the course of the hearing, (6) hold conferences for the settlement or simplification of the issues by consent of the parties, (7) dispose of procedural requests or similar matters, (8) make decisions or recommend decisions in conformity with section 8, and (9) take any other action authorized by agency rule consistent with this Act.”
  It should be noted that representation proceedings such as were involved in Labor Board v. Duval Jewelry Co., supra, are excepted from some of the requirements of the Administrative Procedure Act. See § 4.
  See § 11 (1), supra, note 1.
  Section 11 (1) was rewritten by the Taft-Hartley Act, 61 Stat. 136, 29 U. S. C. § 161 et seq. Senator Taft said concerning it, 93 Cong. Rec. 6445:
  “Section 11 authorizes the Board to conduct hearings and investigations and to subpena witnesses. This section was not changed in the Senate amendment and was modified by the conferees in only one respect. The Board is required upon application of any party to issue a subpena as a matter of course. A procedure is established whereby the person subpenaed may move to quash the subpena if the evidence requested thereby does not relate to any matter under investigation or does not describe with sufficient particularity the evidence required.” (Italics added.)
  See Labor Board v. John S. Barnes Corp., 178 F. 2d 156; Edwards v. Labor Board, 189 F. 2d 970; Jackson Packing Co. v. Labor Board, 204 F. 2d 842; Labor Board v. Gunaca, 135 F. Supp. 790, aff’d 230 F. 2d 542.
  Section 3 (d) reads as follows:
  “There shall be a General Counsel of the Board who shall be appointed by the President, by and with the advice and consent of the Senate, for a term of four years. The General Counsel of the Board shall exercise general supervision over all attorneys employed by the Board (other than trial examiners and legal assistants to Board members) and over the officers and employees in the regional offices. He shall have final authority, on behalf of the Board, in respect of the investigation of charges and issuance of complaints under section 10, and in respect of the prosecution of such complaints before the Board, and shall have such other duties as the Board may prescribe or as may be provided by law.”
  Section 3 (d) of the Act effected an important change over the earlier Wagner Act. It was designed to separate the prosecuting from the adjudicating function, to place the former in the General Counsel, and to make him an independent official appointed by the President and confirmed by the Senate for a term of years. See H. R. Rep. No. 245, 80th Cong., 1st Sess. 26; H. R. Rep. No. 510, 80th Cong., 1st Sess. 37; statement of Senator Taft, 93 Cong. Rec. 6859.
choices: attorney general of the United States, or his office specified state board or department of education city, town, township, village, or borough government or governmental unit state commission, board, committee, or authority county government or county governmental unit, except school district court or judicial district state department or agency governmental employee or job applicant female governmental employee or job applicant minority governmental employee or job applicant minority female governmental employee or job applicant not listed among agencies in the first Administrative Action variable retired or former governmental employee U.S. House of Representatives interstate compact judge state legislature, house, or committee local governmental unit other than a county, city, town, township, village, or borough governmental official, or an official of an agency established under an interstate compact state or U.S. supreme court local school district or board of education U.S. Senate U.S. senator foreign nation or instrumentality state or local governmental taxpayer, or executor of the estate of state college or university United States State person accused, indicted, or suspected of crime advertising business or agency agent, fiduciary, trustee, or executor airplane manufacturer, or manufacturer of parts of airplanes airline distributor, importer, or exporter of alcoholic beverages alien, person subject to a denaturalization proceeding, or one whose citizenship is revoked American Medical Association National Railroad Passenger Corp. amusement establishment, or recreational facility arrested person, or pretrial detainee attorney, or person acting as such;includes bar applicant or law student, or law firm or bar association author, copyright holder bank, savings and loan, credit union, investment company bankrupt person or business, or business in reorganization establishment serving liquor by the glass, or package liquor store water transportation, stevedore bookstore, newsstand, printer, bindery, purveyor or distributor of books or magazines brewery, distillery broker, stock exchange, investment or securities firm construction industry bus or motorized passenger transportation vehicle business, corporation buyer, purchaser cable TV car dealer person convicted of crime tangible property, other than real estate, including contraband chemical company child, children, including adopted or illegitimate religious organization, institution, or person private club or facility coal company or coal mine operator computer business or manufacturer, hardware or software consumer, consumer organization creditor, including institution appearing as such; e.g., a finance company person allegedly criminally insane or mentally incompetent to stand trial defendant debtor real estate developer disabled person or disability benefit claimant distributor person subject to selective service, including conscientious objector drug manufacturer druggist, pharmacist, pharmacy employee, or job applicant, including beneficiaries of employer-employee trust agreement, employee health and welfare fund, or multi-employer pension plan electric equipment manufacturer electric or hydroelectric power utility, power cooperative, or gas and electric company eleemosynary institution or person environmental organization employer. If employer's relations with employees are governed by the nature of the employer's business (e.g., railroad, boat), rather than labor law generally, the more specific designation is used in place of Employer. farmer, farm worker, or farm organization father female employee or job applicant female movie, play, pictorial representation, theatrical production, actor, or exhibitor or distributor of fisherman or fishing company food, meat packing, or processing company, stockyard foreign (non-American) nongovernmental entity franchiser franchisee lesbian, gay, bisexual, transexual person or organization person who guarantees another's obligations handicapped individual, or organization of devoted to health organization or person, nursing home, medical clinic or laboratory, chiropractor heir, or beneficiary, or person so claiming to be hospital, medical center husband, or ex-husband involuntarily committed mental patient Indian, including Indian tribe or nation insurance company, or surety inventor, patent assigner, trademark owner or holder investor injured person or legal entity, nonphysically and non-employment related juvenile government contractor holder of a license or permit, or applicant therefor magazine male medical or Medicaid claimant medical supply or manufacturing co. racial or ethnic minority employee or job applicant minority female employee or job applicant manufacturer management, executive officer, or director, of business entity military personnel, or dependent of, including reservist mining company or miner, excluding coal, oil, or pipeline company mother auto manufacturer newspaper, newsletter, journal of opinion, news service radio and television network, except cable tv nonprofit organization or business nonresident nuclear power plant or facility owner, landlord, or claimant to ownership, fee interest, or possession of land as well as chattels shareholders to whom a tender offer is made tender offer oil company, or natural gas producer elderly person, or organization dedicated to the elderly out of state noncriminal defendant political action committee parent or parents parking lot or service patient of a health professional telephone, telecommunications, or telegraph company physician, MD or DO, dentist, or medical society public interest organization physically injured person, including wrongful death, who is not an employee pipe line company package, luggage, container political candidate, activist, committee, party, party member, organization, or elected official indigent, needy, welfare recipient indigent defendant private person prisoner, inmate of penal institution professional organization, business, or person probationer, or parolee protester, demonstrator, picketer or pamphleteer (non-employment related), or non-indigent loiterer public utility publisher, publishing company radio station racial or ethnic minority person or organization protesting racial or ethnic segregation or discrimination racial or ethnic minority student or applicant for admission to an educational institution realtor journalist, columnist, member of the news media resident restaurant, food vendor retarded person, or mental incompetent retired or former employee railroad private school, college, or university seller or vendor shipper, including importer and exporter shopping center, mall spouse, or former spouse stockholder, shareholder, or bondholder retail business or outlet student, or applicant for admission to an educational institution taxpayer or executor of taxpayer's estate, federal only tenant or lessee theater, studio forest products, lumber, or logging company person traveling or wishing to travel abroad, or overseas travel agent trucking company, or motor carrier television station union member unemployed person or unemployment compensation applicant or claimant union, labor organization, or official of veteran voter, prospective voter, elector, or a nonelective official seeking reapportionment or redistricting of legislative districts (POL) wholesale trade wife, or ex-wife witness, or person under subpoena network slave slave-owner bank of the united states timber company u.s. job applicants or employees Army and Air Force Exchange Service Atomic Energy Commission Secretary or administrative unit or personnel of the U.S. Air Force Department or Secretary of Agriculture Alien Property Custodian Secretary or administrative unit or personnel of the U.S. Army Board of Immigration Appeals Bureau of Indian Affairs Bonneville Power Administration Benefits Review Board Civil Aeronautics Board Bureau of the Census Central Intelligence Agency Commodity Futures Trading Commission Department or Secretary of Commerce Comptroller of Currency Consumer Product Safety Commission Civil Rights Commission Civil Service Commission, U.S. Customs Service or Commissioner of Customs Defense Base Closure and REalignment Commission Drug Enforcement Agency Department or Secretary of Defense (and Department or Secretary of War) Department or Secretary of Energy Department or Secretary of the Interior Department of Justice or Attorney General Department or Secretary of State Department or Secretary of Transportation Department or Secretary of Education U.S. Employees' Compensation Commission, or Commissioner Equal Employment Opportunity Commission Environmental Protection Agency or Administrator Federal Aviation Agency or Administration Federal Bureau of Investigation or Director Federal Bureau of Prisons Farm Credit Administration Federal Communications Commission (including a predecessor, Federal Radio Commission) Federal Credit Union Administration Food and Drug Administration Federal Deposit Insurance Corporation Federal Energy Administration Federal Election Commission Federal Energy Regulatory Commission Federal Housing Administration Federal Home Loan Bank Board Federal Labor Relations Authority Federal Maritime Board Federal Maritime Commission Farmers Home Administration Federal Parole Board Federal Power Commission Federal Railroad Administration Federal Reserve Board of Governors Federal Reserve System Federal Savings and Loan Insurance Corporation Federal Trade Commission Federal Works Administration, or Administrator General Accounting Office Comptroller General General Services Administration Department or Secretary of Health, Education and Welfare Department or Secretary of Health and Human Services Department or Secretary of Housing and Urban Development Interstate Commerce Commission Indian Claims Commission Immigration and Naturalization Service, or Director of, or District Director of, or Immigration and Naturalization Enforcement Internal Revenue Service, Collector, Commissioner, or District Director of Information Security Oversight Office Department or Secretary of Labor Loyalty Review Board Legal Services Corporation Merit Systems Protection Board Multistate Tax Commission National Aeronautics and Space Administration Secretary or administrative unit of the U.S. Navy National Credit Union Administration National Endowment for the Arts National Enforcement Commission National Highway Traffic Safety Administration National Labor Relations Board, or regional office or officer National Mediation Board National Railroad Adjustment Board Nuclear Regulatory Commission National Security Agency Office of Economic Opportunity Office of Management and Budget Office of Price Administration, or Price Administrator Office of Personnel Management Occupational Safety and Health Administration Occupational Safety and Health Review Commission Office of Workers' Compensation Programs Patent Office, or Commissioner of, or Board of Appeals of Pay Board (established under the Economic Stabilization Act of 1970) Pension Benefit Guaranty Corporation U.S. Public Health Service Postal Rate Commission Provider Reimbursement Review Board Renegotiation Board Railroad Adjustment Board Railroad Retirement Board Subversive Activities Control Board Small Business Administration Securities and Exchange Commission Social Security Administration or Commissioner Selective Service System Department or Secretary of the Treasury Tennessee Valley Authority United States Forest Service United States Parole Commission Postal Service and Post Office, or Postmaster General, or Postmaster United States Sentencing Commission Veterans' Administration War Production Board Wage Stabilization Board General Land Office of Commissioners Transportation Security Administration Surface Transportation Board U.S. Shipping Board Emergency Fleet Corp. Reconstruction Finance Corp. Department or Secretary of Homeland Security Unidentifiable International Entity