An object is to provide a hygienic cushion that has an adequate thickness to provide the repulsive force of or above a specified level and the body-holding property, is light in weight, has excellent air permeability and is washable with water. The core material for cushion 1 comprising the three-dimensional net-like structure, which is comprised of a polyethylene thermoplastic resin, a polyester thermoplastic elastomer or a mixture of a polyethylene thermoplastic resin and a polyethylene thermoplastic elastomer. 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. 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.