A face authentication system includes a registration device that acquires a face image for registration of a user in a facility and specific information used for specifying the user, one or more face authentication machines that acquire a face image for authentication of the user captured when the event is generated, a face management server that is connected to the registration device via a network, and accumulates the face image for registration and the specific information in association with each other, and a face collation server that generates face feature data from the face image for registration and the face image for authentication, and performs collation processing between pieces of the face feature data.