The resin molded article is molded by using an electrode sheet as an insert in a state where one surface of the electrode sheet is closely attached to an inner surface which serves as the inner side of the operation surface. The electrode sheet is formed by using, as a base material, a thermoplastic synthetic resin sheet which outputs an electrical signal according to the amount of change of electrostatic capacitance generated by a contact operation with respect to the operation surface. At least a whole or a part of the inner surface is formed in a three-dimensionally curved surface, and a passage is formed in the electrode sheet so as to allow a molten resin following in through a gate formed in a die which comes into contact with the other surface of the electrode sheet during molding to pass toward one surface side of the electrode sheet.