Provided is a waist belt including: a nonstretchable left main belt, a nonstretchable right main belt, a nonstretchable left inner tightening belt, a nonstretchable left outer tightening belt, a nonstretchable right inner tightening belt, a nonstretchable right outer tightening belt, a stretchable left subsidiary tightening belt, a stretchable right subsidiary tightening belt, a right folding-back ring, a left folding-back ring, a left linking ring, a left linking ring and an insertion ring. Circumferential differences at the waist portion of a user are absorbed. Even when the user moves, the function of tightening the waist portion is not impaired.