PROBLEM TO BE SOLVED: To secure a gap of an air passage formed when a waist stretchable member is contracted.SOLUTION: On a front body section and/or a back body section, a cushion part 40 is formed. The cushion part 40 includes an inner sheet 41, an outer sheet 42, one or more waist stretchable members 43, and a cushion formation sheet 44. The waist stretchable members 43 are fixed between the inner sheet 41 and the outer sheet 42 in the state that they are stretched along a width direction. The cushion formation sheet 44 is put on the inner sheet 41 and/or the outer sheet 42 and is joined in the way that a joint part 51 and a non-joint part 52 follow each other in the width direction. The joint part 51 is formed by two or more linear joint lines 53 extending in a longitudinal direction being arranged side by side, and a gap (second gap D) between columns of the joint lines 53 inside the joint part is narrower than a gap (first gap D) between the joint parts.SELECTED DRAWING: Figure 4【課題】ウエスト伸縮部材が収縮したときに形成される通気路の間隔を広く確保する。【解決手段】前身頃と後身頃の両方又はいずれか一方に，クッション部４０が形成されている。クッション部４０は，内側シート４１と，外側シート４２と，一又は複数のウエスト伸縮部材４３と，クッション形成シート４４と，を含む。ウエスト伸縮部材４３は，幅方向に沿って伸長した状態で，内側シート４１と外側シート４２の間に固定されている。クッション形成シート４４は，内側シート４１と外側シート４２の両方又はいずれか一方に重ねられて，幅方向に接合部５１と非接合部５２が交互に連続するように接合されている。接合部５１は，長手方向に沿って延びる直線状の接合線５３が２列以上に並んで形成されており，接合部内の接合線５３の列の間の間隔（第２の間隔Ｄ２）は，接合部同士の間の間隔（第１の間隔Ｄ１）よりも狭い。【選択図】図４
