A method of manufacturing a composite molded member, which includes the steps of: setting the main body inside an injection mold; closing the injection mold to fix the main body inside the injection mold; and forming the cushion members on the edges of the main body through heat and pressure of the injected elastic polymer material. The elastic polymer material is injected from an injection gate into one of the first and second edges at the back surface side of the main body of the molding cavities to flow the elastic polymer material into one of the molding cavities. The elastic polymer material flows into the other of the molding cavities through the connecting flow path, and fills the molding cavities with the elastic polymer material.