To provide a device for correcting the feed lengths of photosensitive materials which is capable of suppressing the occurrence of a variation in feed length regardless of the kinds of the photosensitive materials.

This device has a paper cutter 6 which cuts long-sized paper P drawn out of paper magazines 1a and 1b to a prescribed print size, kind detecting sensors 2a and 2b which detect the kinds of the paper P, a feed length control means 25a which controls the feed length of the paper P in order to cut the paper P to the prescribed print size and a feed length correcting means 25b which corrects the feed length in accordance with the detected kinds of the paper P.