PURPOSE: To enable to extrude large volume of resin and obtain a film of high quality, by a method wherein a large number of functions is divided into a melter and a homogenizer and a rotor is arranged in the intermediate part of them.

CONSTITUTION: Discharge pressure of a melter 11 is detected by a pressure detector 16 feedback of which is applied to a pressure adjusting device 17, through which the discharge pressure is controlled by adjusting a speed of an electric motor A13 through control part A12 of the electric motor. A rotor 18 which is downstream a filter A15 is driven by an electric motor B20 whose speed is adjusted by a control part B19, and molten resin to be supplied from the filter A15 is quantified at every cog of a gear. The stable quantitative molten resin is supplied to a homogenizer 22 on an outlet side of the rotor 18 from the rotor 18, through which a temperature of the resin is lowered to a target temperature and at the same time the titled device possesses a screw equalizing the temperature of the resin. The screw is driven by an electric motor and generates pressure necessary for the resin to pass through a filter B23 and a die 24 located downstream of the screw.