the present invention comprises : a collecting section mounted at one side of the pathway , in which the suction force of a vacuum cleaner for sucking dust is transmitted , and moves at least some of the sucked dust towards one direction ; a dust collecting section made of transparent material coupled with the collecting section , in which the receiving status of the inflow of dust through the collecting section is exposed to the outside ; a discharge section which guides air and dust , which has passed through the dust collecting section , to be discharged into the pathway that transmits the suction force of a vacuum cleaner ; and a foreign material discharge means which guides the flow of air into the inner corner of the dust collecting section by the operation of the user and forcibly discharges the remaining dust in the dust collection section to the outside . according to the present invention , the invention enables the user to check the status of the dust that is sucked and the convenient discharge of the dust collected in the inside of the collecting section .