In so far as a disposable diaper (10) is concerned, a leg stretching unit (75) which stretches in a product longitudinal direction is disposed at an inside of a product widthwise direction than a pair of leg opening units. An area between a backside leg opening unit (35R) and a straight line which passes through a center in the product widthwise direction and which is in parallel to the product longitudinal direction is larger than an area between a foreside leg opening unit (35F) and a straight line which passes through a center of the product longitudinal direction of the leg opening unit and which extends in the product longitudinal direction. A buttocks part stretching unit (77) which is disposed so as to run across a crotch region and the back waistline region and which stretches in the product longitudinal direction is disposed at an outside of the product widthwise direction than the leg stretching unit. A front end of the buttocks part stretching unit is positioned more backward than a center of the product longitudinal direction of the leg opening unit.【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外側には、股下域と前記後胴回り域とに跨って配置され、かつ製品長手方向に伸縮する臀部伸縮部が配置され、臀部伸縮部の前端部は、レッグ開口部の前記製品長手方向の中心よりも後方に位置する。【選択図】図1
