PROBLEM TO BE SOLVED: To provide an underpants type disposable diaper equipped with a waist edge part that makes gathers look straight and is excellent in appearance and is excellent in wearing texture as well.SOLUTION: An underpants type disposable diaper is provided with a non-connected/non-elastic stretch member area 25 in which sheet joint parts 70 are formed by an inner layer 21 and an outer layer 22 in a waist edge part W of an exterior body 12 being intermittently arranged in a width direction and joined by an adhesive 71 stretching in the direction crossing the width direction or welding processing, a waist edge part elastic flexible member 17 is put between the inner layer 21 and the outer layer 22 and is fixed to at least either the inner layer 21 or the outer layer 22 at a position crossing the sheet joint parts 70 and which does not have the sheet joint parts 70 and the waist edge part elastic flexible member 17 at an end part on the side of a non-elastic WO in the waist edge part W of the exterior body 12 and is wider than a gap between the waist edge part elastic flexible member 17 whose vertical direction range is located nearest to the non-elastic WO side and the waist edge part elastic flexible member 17 adjacent to the same.【課題】襞が真直ぐに延びて見栄えに優れるとともに、装着感にも優れるウエスト縁部を備えた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、外装体１２のウエスト縁部Ｗにおける内側層２１及び外側層２２が、幅方向に間欠的に配された、幅方向と交差する方向に連続する接着剤７１又は溶着加工により接合されてシート接合部７０が形成されており、ウエスト縁部弾性伸縮部材１７が内側層２１及び外側層２２間に挟まれるとともに、シート接合部７０と交差する位置で内側層２１及び外側層２２の少なくとも一方に固定されており、外装体１２のウエスト縁部Ｗにおけるウエスト開口部ＷＯ側の端部に、シート接合部７０及びウエスト縁部弾性伸縮部材１７を有さず、かつ縦方向範囲が最もウエスト開口部ＷＯ側に位置するウエスト縁部弾性伸縮部材１７とこれに隣接するウエスト縁部弾性伸縮部材１７との間隔よりも広い、無接合・無弾性伸縮部材領域２５を備えた、パンツタイプ使い捨ておむつにより解決される。【選択図】図５
