A printed material processing device includes: a feature information extracting unit configured to compare read printed-material image information obtained by reading a printed material, and extract a portion equivalent to a difference between the two sets of information as feature information; an image generating unit configured to generate an image of a mark to be additionally printed near a location of the feature information, set first information indicating a positional relationship between the mark and the feature information, set second information indicating a method of extracting the feature information and a feature quantity to be extracted from the feature information, and generate an image of code information to be additionally printed in a position on the printed material, the code information including the first information and the second information; and an image forming unit configured to additionally print the mark and the code information.