PURPOSE: To make the coating film property suitable for specific purposes through free selection of the thickness of the film by extruding a melted thermoplastic resin for coating material in a cylindrical shape from the mold and then, adhering thereof closely to a member at a time when it is cooled to a certain extent.

CONSTITUTION: A thermoplastic resin melted is extruded in a cylindrical shape from the outlet of a crosshead die 4 and a given member is introduced into a cylindrical resin. The gap between the member 1 and the cylindrical resin is kept reduced in the pressure. The cylindrical resin is quickly cooled down solid by an air blown through an air blowoff port 10 and made to stretch as the member 1 moves so that it is tightly attached to the surface of the members as a film 2. The thickness of the resin film can be controlled freely by adjusting the loading speed of the member 1 and the extrusion volume of the melted resin. Withdrawal of finished goods by a withdrawing device 6 permits continuous production of members coated with a synthetic resin film.