NOVELTY - The extruder (100) has a cooling system that is positioned on a cylinder wall and is provided with a refrigerant flow path comprising a first refrigerant supply-discharge opening. A temperature detector (50) detects a temperature of a molten resin extruded from an extrusion opening of a cylinder. A control apparatus (60) controls the temperature difference between the temperature of molten resin and a resin preset temperature by adjusting supply amount to a first refrigerant supply-discharge opening of refrigerant below to a predetermined threshold value.    USE - Twin-screw extruder of apparatus for manufacturing film such as polyester film used on hostile environment condition of outdoor such as solar cell.    ADVANTAGE - The control apparatus controls the temperature difference between the temperature of molten resin and a resin preset temperature by adjusting supply amount to a first refrigerant supply-discharge opening of refrigerant below to a predetermined threshold value so that more exact temperature control of molten resin is attained and the temperature variation of the molten resin in cylinder is suppressed effectively. Thus, the temperature of resin melt-extruded is maintained stably with reduced haze. Hence, the resin is generated effectively with the improved weather resistance. The oxygen concentration is restrained by less than 10 vol.% as for the atmosphere of the raw material supply port so that the deterioration of sealing effect of polyester resin is prevented by a terminal blocking material showing up favorably by the oxygen concentration in the atmosphere of the raw material supply port supplying a polyester resin and a terminal blocking material restrained by less than 10 volume. Thus, the hydrolysis-resistant effect of extruder is improved effectively.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for manufacturing film.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of the film manufacturing apparatus. (Drawing includes non-English language text)    Molding die (40)    Temperature detector (50)    Control apparatus (60)    Twin-screw extruder (100)    Film manufacturing apparatus (200)