A cushion body (10) as an example of a cushioning device includes a polyurethane layer (17) as a cushioning member having a mounting surface of a user, and a mechanism for bending the cushioning member in a direction intersecting the mounting surface. The contained gas cell (31)； the polyurethane layer (17) has a plurality of first portions (peak portions (18A)), which extend in the Y direction as an example of the first direction among the in-plane directions, and are larger than the first portion The second portion (the groove portion (18B)), which is easily deformed in part, is formed integrally with the first portion between the plurality of first portions.作為緩衝裝置的一個例子的墊子主體(10)具備：具有使用者的載置面的作為緩衝構件的聚氨酯層(17)，以及用於使緩衝構件在與載置面交叉的方向上彎曲的機構所包含的氣室(31)；聚氨酯層(17)具有：多個第一部分(峰部(18A))，在面內方向中的作為第一方向的一個例子的Y方向上延伸，以及比第一部分容易變形的第二部分(槽部(18B))，在多個第一部分之間與第一部分形成為一體。
