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.用後即棄式紙尿布(1)係在較一對腳開口部更靠近製品寬度方向內側的位置,配置有朝製品長度方向伸縮之腳伸縮部(75)。後側腳開口部(35R)與通過製品寬度方向的中心並與製品長度方向呈平行的直線之間的面積係較前側腳開口部(35F)與通過腳開口部的製品長度方向中心並朝製品長度方向延伸的直線之間的面積廣。在較腳伸縮部更靠近製品寬度方向外側的位置,配置有跨越胯下區域與前述後腰圍區域而配置且朝製品長度方向伸縮之臀部伸縮部(77)。臀部伸縮部的前端部係位於較腳開口部的前述製品長度方向的中心更後方之位置。90‧‧‧扣帶30‧‧‧後腰圍區域35R‧‧‧後側腳開口部77‧‧‧臀部伸縮部L2‧‧‧中心線77F‧‧‧前端部35‧‧‧腳開口部125‧‧‧缺口25‧‧‧胯下區域O4‧‧‧中心115‧‧‧缺口D2‧‧‧距離35I‧‧‧內側端部35F‧‧‧前側腳開口部20‧‧‧前腰圍區域95‧‧‧目標部81‧‧‧彈性構件80‧‧‧腳側皺褶75‧‧‧腳伸縮部37‧‧‧凹部O2‧‧‧中心O1‧‧‧中心O3‧‧‧中心L‧‧‧製品長度方向200‧‧‧褲襠伸縮部36‧‧‧凸部D1‧‧‧距離91‧‧‧基材薄片92‧‧‧鉤薄片10‧‧‧用後即棄式紙尿布70‧‧‧側翼片40‧‧‧吸收體L1‧‧‧直線50‧‧‧頂面薄片W‧‧‧製品寬度方向85‧‧‧腳圍伸縮部