PROBLEM TO BE SOLVED: To provide a pants type diaper having a structure for not easily causing looseness of an abdominal part of an exterior sheet or sliding-down and floating-up of a lower back part even when worn by a wearer with hump back.SOLUTION: The pants type disposable diaper includes an exterior sheet having a front section F and a back section B and an interior body 10 including an absorber, fixed to the inner surface of the exterior sheet, and in the pants type disposable diaper, by bonding the front section F and back section B of the exterior sheet at both side parts, a waist opening and a pair of left and right leg openings are formed. In the waist opening, the back section B is extended more in an upper direction than the front section F, a belt part 33 is extended from both side parts in the upward extension part of the back section B, and the top end part 35 is fixed to the fixation part 32 of the front section.
