To provide a printing plate inspection apparatus to accurately and efficiently inspect the printing plate.

Images for printing (C image 11, M image 13, Y image 15 and K image 17) are produced by a RIP (raster image processor) process and stored in a data base 3. A printing plate 9 is placed at a distance where the image projected on the plate 9 by a projector 7 is unmagnified. Specified image data in the C image 11, M image 13, Y image 15 and K image 17 for printing corresponding to the placed printing plate 9 is read out by a computer 5 and sent to the projector 7. The image is projected onto the printing plate 9 by the projector 7, and the image on the printing plate 9 is compared with the image projected by the projector 7 to inspect the printing plate 9. This plate inspection process is repeated by the number of plates.