A preexposure apparatus comprises a film supply station ST1 for arranging a film cartridge 14 containing a film 12 accommodated therein, a film-drawing station-ST3 for automatically drawing the film 12 over its entire length, an exposure station ST5 for exposing a predetermined portion of the drawn film 12 with an image by the aid of an exposure section 32, a winding station ST6 for automatically rewinding the film 12 after the exposure into the film cartridge 14, and a withdrawing station ST8 for withdrawing the film cartridge 14. Accordingly, the predetermined portion of the film can be preexposed with a desired image automatically and efficiently.