PROBLEM TO BE SOLVED: To provide a disposable diaper capable of preventing the entrainment of product width direction end parts while appropriately covering buttocks when put on.SOLUTION: In a disposable diaper 1, leg expansion/contraction parts 75, which expand and contract in the product longitudinal direction, are disposed on the product width direction inner side of each of a pair of leg openings. An area between a rear leg opening and a straight line which passes through the center of the product width direction and is parallel to the product longitudinal direction is larger than an area between a front leg opening and a straight line which passes through the center of the product width direction and extends to the product longitudinal direction. Each of a pair of buttocks expansion/contraction parts 77, which expand and contract in the product longitudinal direction, is disposed on both product width direction outer sides of the leg expansion/contraction parts. A distance La in the product width direction between the outer end part of a fastening tape in the product width direction and the buttocks expansion/contraction parts is shorter than a distance Lb in the product width direction between the center of the product width direction of the disposable diaper and the outer end part of the leg expansion/contraction parts in the product width direction.【課題】臀部を適切に覆いながら、装着時に製品幅方向端部の巻き込みを防止することができる使い捨ておむつを提供する。【解決手段】使い捨ておむつ1は、一対のレッグ開口部よりも製品幅方向内側に、製品長手方向に伸縮するレッグ伸縮部75が配置される。後側レッグ開口部と、製品幅方向における中心を通り製品長手方向に平行な直線との間の面積は、前側レッグ開口部と、レッグ開口部の製品長手方向中心を通り製品長手方向に延びる直線との間の面積よりも広い。レッグ伸縮部よりも製品幅方向両外側には、製品長手方向に伸縮する一対の臀部伸縮部77が配置される。ファスニングテープの製品幅方向外側端部と臀部伸縮部との製品幅方向における距離Laは、使い捨ておむつの製品幅方向中心とレッグ伸縮部の製品幅方向外側端部との製品幅方向における距離Lbよりも短い【選択図】図１
