Abstract: In a mechanism for feeding a film, used in a camera, etc., in which a film having one perforation formed at a specified position relative to each frame or a film having a plurality of perforations formed at specified positions relative to each frame with unequal intervals therebetween as a whole is used, a sprocket 13 is employed for controlling to forward the film frame by frame. The sprocket is locked by a lever before an initial forwarding of thefilm is carried out, and it is unlocked from the lever when the film is forwarded to move the lever, so that the relationship of engagement between a tooth of the sprocket and the perforations of the film is ensured to be constant and synchronous during the initial feeding of the film.