In the method, after the pattern-bearing film is fed to the female mold, the distal end of the film is fixed under a lower portion of the female mold, and at the same time the film is retreated by a force from the film supply portion. Thus, this tightens up the film so that the slacks or wrinkles cannot be formed on the film. Therefore, the film can be fortunately spread around the parting surface of the female mold. In the apparatus, the film suppressing frame is pressed to the female mold through the sliding rod arranged in the female mold, in such a manner that the female mold embraces the frame. Thus, the pressing of the frame is performed by a simple structure, and the film is accurately positioned to the internal surface of the female mold. Also, the film suppressing frame is constituted to advance from and retreat to the female mold. Thus, this causes a space between the both molds and an outside standby position to be useless. A space around the apparatus can be effectively utilized.