Provided is a waist belt (1) including: a left inner tightening belt (43) extended from a left main belt (2) and folded back through a left folding-back ring (33) of a right main belt (3) a right inner tightening belt (53) extended from the right main belt (3) and folded back through a right folding-back ring (23) of the left main belt (2) a left subsidiary tightening belt (6) extended leftward from the right main belt (3) a right subsidiary tightening belt (7) extended rightward from the left main belt (2) a left outer tightening belt (44) connected to the left subsidiary tightening belt (6), folded back through a left fixation ring (45) folded back through a left linking ring (433) of the left inner tightening belt (43), and connected to the left main belt (2), the left fixation ring (45) being configured to be attached to and detached from the left main belt (2) and a right outer tightening belt (54) connected to the right subsidiary tightening belt (7), folded back through a right fixation ring (55), folded back through a right linking ring (533) of the right inner tightening belt (53), and connected to the right main belt (3), the right fixation ring (55) being configured to be attached to and detached from the right main belt (3). The waist belt 1 absorbs differences in circumferential length of a waist portion, and does not impair the function of squeezing tight around the waist even when a user moves.
