Intermediate films are automatically removed from an intermediate film stack. The removed intermediate film is positioned on a table and cut to a desired size, and then placed on one of two curved glass sheets which has its convex side facing up. Thereafter, the other glass sheet is positioned over said one of the glass sheets, and both the glass sheets are positioned at the same time. Then, the lower glass sheet is moved upwardly against the upper glass sheet so that the glass sheets are superposed with the intermediate film interposed therebetween.