To provide a collation system allowing an efficient censorship for a browsed image data brought into a browsable state, at a site on a network.

This collation system has an image database 2, registered with a plurality of registered image data, a retrieval light generating means 3 for generating a retrieval light, based on the browsed image data; and a collation means 4 for collating the image data 13 browsed with the registered image data; the image database has an information light 32 generated based on the registered image data; a reference mark light 33 generated based on a reference mark, and a holographic recording medium provided with a hologram recording layer 21 recorded with the image data by an interference fringe 24. The collation means emits the retrieval light 36, generated by the retrieval light generating means, to the hologram recording layer and detects the regenerated reference mark 37 and collates the image data browsed with the registered image data.