A waist belt comprising: a nonstretchable left body belt; a nonstretchable right body belt; a nonstretchable left inner tightening belt; a nonstretchable left outer tightening belt; a nonstretchable right inner tightening belt; and a nonstretchable right outer tightening belt, wherein the left body belt, the right body belt, the left inner tightening belt, the left outer tightening belt, the right inner tightening belt, and the right outer tightening belt are arrayed in a line, with a right fold ring provided at a right end portion of the left body belt and with a left fold ring provided at a left end portion of the right body belt, the left end portion of the left body belt and the right end portion of the right body belt are allowed to be freely connected to and disconnected from each other, the left inner tightening belt, with a right end portion thereof attached to the right end portion of the left body belt, is passed through the left fold ring and folded back leftward, and a left connecting ring is provided at a left end portion thereof that has passed through the right fold ring, the right inner tightening belt, with a left end portion thereof attached to the left end portion of the right body belt, is passed through the right fold ring and folded back rightward, and a right connecting ring is provided at a right end portion thereof, the left outer tightening belt, with a right end portion thereof fixed to an outer surface of the left body belt, is pulled rightward, passed through the left connecting ring, and folded back leftward, and a left end portion thereof is configured to be detachably attached to the left body belt, and the right outer tightening belt, with a left end portion thereof fixed to an outer surface of the right body belt, is pulled leftward, passed through the right connecting ring, and folded back rightward, and a right end portion thereof is configured to be detachably attached to the right body belt. a nonstretchable left body belt; a nonstretchable right body belt; a nonstretchable left inner tightening belt; a nonstretchable left outer tightening belt; a nonstretchable right inner tightening belt; and a nonstretchable right outer tightening belt, wherein the left body belt, the right body belt, the left inner tightening belt, the left outer tightening belt, the right inner tightening belt, and the right outer tightening belt are arrayed in a line, with a right fold ring provided at a right end portion of the left body belt and with a left fold ring provided at a left end portion of the right body belt, the left end portion of the left body belt and the right end portion of the right body belt are allowed to be freely connected to and disconnected from each other, the left inner tightening belt, with a right end portion thereof attached to the right end portion of the left body belt, is passed through the left fold ring and folded back leftward, and a left connecting ring is provided at a left end portion thereof that has passed through the right fold ring, the right inner tightening belt, with a left end portion thereof attached to the left end portion of the right body belt, is passed through the right fold ring and folded back rightward, and a right connecting ring is provided at a right end portion thereof, the left outer tightening belt, with a right end portion thereof fixed to an outer surface of the left body belt, is pulled rightward, passed through the left connecting ring, and folded back leftward, and a left end portion thereof is configured to be detachably attached to the left body belt, and the right outer tightening belt, with a left end portion thereof fixed to an outer surface of the right body belt, is pulled leftward, passed through the right connecting ring, and folded back rightward, and a right end portion thereof is configured to be detachably attached to the right body belt.