PROBLEM TO BE SOLVED: To provide an underpants type disposable diaper which is excellent in fitting property at a gluteal cleft and both of across-the-width sides thereof and which hardly causes turn-up on the edges of leg openings in a rear part.SOLUTION: An underpants type disposable diaper 1 is structured as follows: curved elastic members 26, 28 curving along leg opening edges 29, and long-and-thin elastic members 27 across-the-width of a gluteal cleft part, which extended in a width direction across a gluteal cleft-facing part, are fixed to an exterior sheet 20 while elongated in the extending direction at a prescribed elongation ratio the back side curved elastic member 26 and the elastic members 27 across-the-width of the gluteal cleft part are cut fine at portions adjacent to the sides of the gluteal cleft-facing part to form non-contractile parts 43 on which contractile force does not act and the lateral sides relative to the non-contractile parts 43 are entirely formed as parts 44 where the elastic members 27 across-the-width of the gluteal cleft part do not exist.COPYRIGHT: (C)2013,JPO&INPIT【課題】臀裂及びその幅方向両側におけるフィット性に優れ、後身頃におけるレッグ開口の縁部が捲れ難い、パンツタイプ使い捨ておむつを提供する。【解決手段】上記課題は、レッグ開口縁29に沿って湾曲する湾曲弾性部材26,28、及び臀裂対向部を横切って幅方向に延在する細長状の臀裂部幅方向弾性部材27が、その延在方向に所定の伸長率で伸長された状態で外装シート20に固定されており、臀裂対向部の側方に隣接する部位で背側湾曲弾性部材26及び臀裂部幅方向弾性部材27が細かく切断されて収縮力が作用しない非収縮部分43が形成されるとともに、この非収縮部分43より側方全体が臀裂部幅方向弾性部材27の非存在部分44とされている、パンツタイプ使い捨ておむつ1により解決される。【選択図】図13
