The invention discloses an apparatus and method for manufacturing an optical film, aiming at providing an apparatus and method that can easily determine sets of rolls that may cause defects. The apparatus for manufacturing the optical film manufactures the optical film by processing a transported film. The apparatus has a plurality of rollers which are in contact with the film. The plurality of rollers are divided into a plurality of groups based on the fixed value of each roller. If a mark at one point in the circumferential direction of each roller is transferred onto the film, the fixed value is determined in such a manner that the fixed value corresponds to distance of the mark on the film that is processed.