What was the legal document signed at Japan’s formal surrender ceremony called?

The legal document signed at Japan’s formal surrender ceremony was the Japanese Instrument of Surrender.

The document was signed on September 2, 1945, aboard the battleship USS Missouri in Tokyo Bay. It recorded Japan’s acceptance of the Potsdam Declaration and directed Japanese forces to cease hostilities and surrender to the designated Allied commanders.

Japanese Foreign Minister Mamoru Shigemitsu signed for the Japanese government, and General Yoshijirō Umezu signed for the Imperial General Headquarters. Douglas MacArthur signed for the Allied powers, followed by representatives of the United States, China, the United Kingdom, the Soviet Union, Australia, Canada, France, and the Netherlands.

The Instrument of Surrender is not the same as a peace treaty. It ended active hostilities and established surrender arrangements, while a later treaty dealt with Japan’s formal postwar peace settlement. The signing ceremony therefore marked the military conclusion of World War II involving Japan, even though occupation and diplomatic negotiations continued afterward.