A plurality of joint portions (3) spaced apart from each other in the expansion / contraction direction (Df) are formed by a pair of sheets (1) and (2) on the first surfaces (1f) and (2f) of the pair of sheets (1) and (2). It is formed by welding to each other without using an adhesive, and holds the elastic member (F) and extends in a direction (Dp) intersecting the expansion / contraction direction (Df) of the elastic member (F). The elastic sheet (10) includes a plurality of ridges (P) appearing between the plurality of joints (3) in a state where F) is contracted, and each of the joints (3) includes the elastic member (F). ) Between the plurality of strong joints (3s) arranged on both sides in the intersecting direction (Dp) and the elastic members (F) adjacent to each other, and among the plurality of strong joints (3s) A weak joint (3w) disposed between the strong joints (3s) adjacent to each other.伸縮方向（Ｄｆ）に互いに離間した複数の接合部（３）は一対のシート（１），（２）の第１面（１ｆ），（２ｆ）において一対のシート（１），（２）が接着剤を介することなく互いに溶着されて形成され、かつ、弾性部材（Ｆ）を保持し、弾性部材（Ｆ）の伸縮方向（Ｄｆ）に交差する方向（Ｄｐ）に延びており、弾性部材（Ｆ）が収縮している状態において複数の接合部（３）の間に現れる複数の襞（Ｐ）を伸縮シート（１０）が備え、前記各接合部（３）は、前記各弾性部材（Ｆ）の前記交差する方向（Ｄｐ）の両側に配置された複数の強接合部（３ｓ）と、互いに隣り合う弾性部材（Ｆ）の間において、かつ、前記複数の強接合部（３ｓ）のうち互いに隣り合う強接合部（３ｓ）の間に配置された弱接合部（３ｗ）とを包含する。
