In this disposable diaper (10), the length (W1) between the ends of a first leg-encircling opening region (R1) in the product widthwise direction (W) at an intersection point (G) is configured in a manner so as to be shorter than the length between the ends of the first leg-encircling opening region (R1) in the product widthwise direction (W) at a region at the rear torso-encircling region (30) side of the intersection point (G), the length (W2) between the ends of a second leg-encircling opening region (R2) in the product widthwise direction (W) is configured in a manner so as to be the shortest in a predetermined region (R), and the length (W1) of the first region (R1) in the product widthwise direction (W) at the intersection point (G) is configured in a manner so as to be longer than the length (W2) of the second region (R2) in the product widthwise direction (W) in the predetermined region (R).在用後即棄式紙尿布(10),在交點(G)的製品寬幅方向(W)的第1腿圍開口區域(R1)的端部彼此的長度(W1),是構成比交點(G)更位在後腰圍域(30)側的區域的製品寬幅方向(W)的第1腿圍開口區域(R1)的端部彼此的長度更短,在製品寬幅方向(W)的第2腿圍開口區域(R2)的端部彼此的長度(W2),是構成在預定區域(R)變的最短,在交點(G)的製品寬幅方向(W)的第1區域(R10)的長度(W1),是構成比位在預定區域(R)的製品寬幅方向(W)的第2區域(R20)的長度(W2)更長。10‧‧‧用後即棄式紙尿布20‧‧‧前腰圍域25‧‧‧胯下域30‧‧‧後腰圍域35‧‧‧腿圍開口部40‧‧‧吸收體60a‧‧‧背面薄片70‧‧‧側翼75‧‧‧腿伸縮部75‧‧‧腿彈性構件80‧‧‧大腿側摺邊81‧‧‧接合部分82‧‧‧自由端部分83‧‧‧彈性構件90‧‧‧扣帶90a‧‧‧目標帶片101‧‧‧臀部側彈性構件110‧‧‧低剛性區域200a‧‧‧胯下伸縮部R1‧‧‧第1腿圍開口區域G‧‧‧交點R2‧‧‧第2腿圍開口區域R‧‧‧預定區域A‧‧‧第1曲線B‧‧‧第2曲線D1‧‧‧距離E1‧‧‧端部E2‧‧‧端部L‧‧‧製品長方向O‧‧‧中心線X‧‧‧線W‧‧‧製品寬幅方向W1、W2‧‧‧長度
