Abstract: An apparatus for forming a cross-oriented film which apparatus includes a device for maintaining the temperature of a thermoplastic synthetic resin tubular film below the melting point, and above the secondary transition temperature thereof, a twist-preventing device for pressing and feeding the tubular film in the film-forming direction, a cross-orientation device for holding the tubular film and for rotating the same, while vertically disposed, relative to the film-forming direction at a peripheral speed two or more times as fast as the feeding speed of the twist-preventing device, and a take-up device for successively flattening the tubular film into two layers.