A plastic molding die provided with a cavity where a plastic material is put in, wherein a part of an inner surface of the cavity is configured with an elastic body. A molding portion corresponding to a molding surface of a molded product is disposed on the inner surface of the cavity, and the elastic body is arranged on a portion other than the molding portion of the inner surface of the cavity. The plastic molding die may be a molding die for compression molding. The elastic body is made of rubber, and has an upper temperature limit higher than a glass-transition temperature of the plastic material. The degree of rubber hardness of the elastic body is from 50 to 100.