Providing a sanitary cushion that is light and has good breathability, water washability, and has a rebound force and body shape retention above a certain level with an appropriate thickness. A thermoplastic resin different from the first layer on one or both sides of the first layer of a three-dimensional network structure comprising a polyethylene-based thermoplastic resin, a polyester-based thermoplastic elastomer, or a mixture of a polyethylene-based thermoplastic resin and a polyethylene-based thermoplastic elastomer In the case of a polyethylene-based thermoplastic resin, the rebound resilience of the three-dimensional network structure is 13 cm or more, the hysteresis loss does not exceed 34%, does not fall below 13%, and the temperature is 90 ° C. at a temperature of 90 ° C. Three-dimensional network structure in the longitudinal direction after a dry hot air test for 30 minutes at 130 ° C. for a polyester thermoplastic elastomer for 30 minutes or at 90 ° C. for 30 minutes for a mixture of a polyethylene thermoplastic resin and a polyethylene thermoplastic elastomer It is the intermediate material 1 for cushions whose thermal elongation rate before and after a dry hot-air test is 0 to 8%.適切な厚みで一定水準以上の反発力と体型保持性を有しながらも軽く、通気性に優れ、水洗い可能で衛生的なクッションを提供する。 ポリエチレン系熱可塑性樹脂、ポリエステル系熱可塑性エラストマー、又はポリエチレン系熱可塑性樹脂とポリエチレン系熱可塑エラストマーの混合物からなる立体網状構造体の第１層の片面又は両面に、第１層と異なる熱可塑性樹脂を含む第２層を積層し、立体網状構造体の反発弾性が１３ｃｍ以上であり、ヒステリシスロスが３４％を超えず、１３％を下回らず、ポリエチレン系熱可塑性樹脂の場合に温度９０℃で３０分間、ポリエステル系熱可塑性エラストマーの場合に１３０℃で３０分間又はポリエチレン系熱可塑性樹脂とポリエチレン系熱可塑エラストマーの混合物の場合に９０℃で３０分間の乾燥熱風試験後、縦方向において立体網状構造体の乾燥熱風試験前後の熱伸長率が０～８％であるクッション用中材１である。
