After Japan was defeated in World War II in August 1945, the Allies demoted the Ministry of Imperial Household to the Imperial Household Office, which was later demoted again to the Imperial Household Agency, and they ranked the Imperial Household Law as one of general laws, which should be under the control of the Constitution of Japan.
昭和20年（1945年）8月に日本が敗戦すると、連合軍は宮内省を宮内府、宮内庁へと次々と降格させ、また皇室典範を日本国憲法下の一般法の一つとして位置づけなおした。