To make a sponge body hygienic and to improve workability, by making an antibacterial agent be contained in soft urethane foam.

A profile worked uneven shape 2 is formed on the surface of soft urethane foam 1, a urethane resin liquid agent containing an antibacterial agent is transcribed thereon to form an antibacterial agent containing layer 3. It is also preferable to form the antibacterial agent containing layer 3 on the whole of the soft urethane foam. In that case, the soft urethane foam is continuously dipped into the antibacterial agent containing liquid in a tank and is dried and cut in a prescribed size to form a sponge body of a product. This constitution is hygienic and can improve workability.