PURPOSE: To obtain a thin film, by a method wherein polypropylene resin is melted and laminated to the surface of an unstretched polycarbonate resin and stretched at a specific temperature.

CONSTITUTION: Uniaxial stretching is performed by extruding a filmy polypropylene resin 3a and polycarbonate resin 3b' through a T die 3 by melting and laminating into a state of three layers, by cooling and solidifying this laminated F1 by a cooling roll 4, and by leading between high-speed stretching rolls 6, 6 through a space between low-speed rolls 5, 5. Then a polypropylene resin film is peeled off by performing heat treatment. It is necessary that a stretching temperature is at least one lower by 70°C than the melting point of the polypropylene resin, at least one lower by 60°C than the glass transition point of the polycarbonate resin, not exceeding one lower by 10°C than the melting point of the polypropylene resin and not exceeding one higher by 20°C than the glass transmission of the polycarbonate resin. The laminate is stretched at least two times or more and five times or less uniaxially.