PROBLEM TO BE SOLVED: To provide an underpants type disposable diaper which receives excrement in a worn state and can stably keep a large space for preventing the leakage.SOLUTION: An absorbent core 23 of an underpants type disposable diaper 10 includes a central absorber 23c and a side absorber 23d and has a bending guide part which comprises an opening extending in a longitudinal direction X between the absorbers. The absorbent core 23 is covered with a surface sheet 21. An extending region 21E formed of the surface sheet 21 extending to a non-skin-facing surface side is joined to a member 42 which is located on a side of an exterior body 30 with respect to the extending region 21E and is adjacent to the extending region 21E. A joining part 43 of the extending region 21E and the member 42 is located outside the bending guide part in a width direction Y. An elastic member 25' is arranged on both side edges of the absorbent core 23, and the side absorber 23d is configured to bend between the elastic member 25' and the joining part 43.SELECTED DRAWING: Figure 5【課題】着用状態において、排泄物を受け入れ、且つその漏れを防止するための広い空間を安定的に維持し得るパンツ型使い捨ておむつを提供すること。【解決手段】パンツ型使い捨ておむつ１０の吸収性コア２３は、中央吸収体２３ｃとサイド吸収体２３ｄを具備し、それらの間に長手方向Ｘに延びる開口からなる屈曲誘導部を有する。吸収性コア２３は表面シート２１で被覆されている。表面シート２１が非肌対向面側に延出した延出部位２１Ｅは、該延出部位２１Ｅよりも外装体３０側に位置し、且つ該延出部位２１Ｅと隣接する部材４２と接合されている。延出部位２１Ｅと前記部材４２との接合部４３が、屈曲誘導部よりも幅方向Ｙの外方にある。吸収性コア２３の両側縁に弾性部材２５’を配し、弾性部材２５’と接合部４３との間でサイド吸収体２３ｄが屈曲するようにした。【選択図】図５
