1. A person recognition apparatus for recognizing a person by a face image, comprising: a storage unit which stores face images of users, and also stores, for a face image having a similar face image, information indicating the existence of the similar face image; a photographing unit which photographs a face image of a user; a first face collator which collates the face image photographed by said photographing unit with a plurality of face images stored in said storage unit; and a second face collator which, in a case where information indicating the existence of a face image similar to the face image collated by said first face collator is stored in said storage unit, performs face image collation by a collating process different from the process performed by said first face collator.