This disposable diaper (10) is provided with a leg extension/contraction section (75) that can extend/contract along the product lengthwise direction and is disposed along a leg-encircling opening section provided to the outside in the product widthwise direction with respect to an absorbent body. A supplemental extension/contraction section (76) that can contract along the product lengthwise direction is provided at the gap between the leg extension/contraction section and the absorbent body in the product widthwise direction the supplemental extension/contraction section is disposed biased to the back torso-encircling region side of the center in the product lengthwise direction and the elongation rate in the product lengthwise direction of the supplemental extension/contraction section is greater than the elongation rate in the product lengthwise direction of the leg extension/contraction section.用後即棄式紙尿布(10),具備:腿部伸縮部(75),沿著設置在比吸收體更靠製品寬度方向外側的腿圍開口部進行配置,並且可以沿著製品長度方向伸縮。製品寬度方向的吸收體與腿部伸縮部之間,設有可朝製品長度方向收縮的輔助伸縮部(76),而輔助伸縮部係配置成從製品長度方向的中心朝後腰圍區域側偏倚,並且輔助伸縮部的製品長度方向的伸長率係比腿部伸縮部的製品長度方向的伸長率更高。10‧‧‧用後即棄式紙尿布20‧‧‧前腰圍區域25‧‧‧胯下區域30‧‧‧後腰圍區域35‧‧‧腿圍開口部40‧‧‧吸收體70‧‧‧側翼部75‧‧‧腿部伸縮部75F‧‧‧腿部伸縮部的前腰圍區域側的端部75I‧‧‧腿部伸縮部的寬度方向內端區域75R‧‧‧腿部伸縮部的後腰圍區域側的端部76F‧‧‧輔助伸縮部的前腰圍區域側的端部76R‧‧‧輔助伸縮部的後腰圍區域側的端部80‧‧‧腿部側縐褶部84‧‧‧收縮部85‧‧‧腰圍伸縮部90‧‧‧扣帶90F‧‧‧扣帶的前腰圍區域側的端部95‧‧‧靶部95R‧‧‧靶部的後腰圍區域側的端部115‧‧‧缺口125‧‧‧缺口200‧‧‧褲襠部200a‧‧‧褲襠部200aF‧‧‧褲襠伸縮部的前腰圍區域側的端部200aR‧‧‧褲襠伸縮部的後腰圍區域側的端部D1‧‧‧腿部伸縮部的前腰圍區域的端部上之間隔D2‧‧‧腿部伸縮部的後腰圍區域的端部上之間隔F1‧‧‧用後即棄式紙尿布之剖面線L‧‧‧製品長度方向W‧‧‧製品寬度方向
