a method for producing a thermoplastic polymer film is disclosed . a melted thermoplastic polymer is extruded from a die onto a rotary cooling body , static electricity is impressed on the rotary cooling , body through a main electrode provided close and parallel to the cooling body and the film is solidified by cooling which method is characterized by providing at least one ungrounded auxiliary electrode composed of a conductive material unconnected to the main electrode and disposed at least on one side of the main electrode parallel to the rotary cooling body .