A core material for cushion comprising a three-dimensional net-like structure in a plate-like form that is formed by spirally tangling a plurality of filaments, which are made of or mainly made of a thermoplastic resin as a raw material, at random and partially bonding the tangles by heat, wherein
the three-dimensional net-like structure has a first layer that includes a thermoplastic resin and a second layer that is stacked on a single surface or both surfaces of the first layer and includes a thermoplastic resin different from the thermoplastic resin of the first layer, wherein
the thermoplastic resin of the first layer has a higher melt temperature than the thermoplastic resin of the second layer,
the first layer or the second layer forms the three-dimensional net-like structure that has a longitudinal direction corresponding to an extrusion direction, a lateral direction and a thickness direction perpendicular to the extrusion direction and is comprised of a polyethylene thermoplastic resin, a polyester thermoplastic elastomer or a mixture of a polyethylene thermoplastic resin and a polyethylene thermoplastic elastomer, wherein
the three-dimensional net-like structure has an impact resilience of not lower than 13 cm, a hysteresis loss of not higher than 34% and not lower than 13%, and a thermal expansion rate of 0 to 8% in the longitudinal direction before and after a hot-air drying test that is performed at a temperature of 90° C. for 30 minutes with regard to the polyethylene thermoplastic resin, that is performed at a temperature of 130° C. for 30 minutes with regard to the polyester thermoplastic elastomer and that is performed at a temperature of 90° C. for 30 minutes with regard to the mixture of the polyethylene thermoplastic resin and the polyethylene thermoplastic elastomer.