A collation system of the present invention includes imaging means for acquiring a captured image of a pre-passage side area with respect to each of gates arranged in parallel with each other, and collation means for performing a collation process on the captured image of the pre-passage side area for each of the gates, between a previously registered target and a target included in the captured image. The collation means performs the collation process on the basis of a target in the captured image corresponding to one of the gates and a target in the captured image corresponding to another one of the gates.