To provide an image formation device, an image formation system, and an authentication device which do not damage confidentiality and accelerate the execution of log-out processing by a user.

An authentication part 402 executes log-in processing when identification information input through an identification information input part 401 satisfies an authentication condition registered previously. A determination part 403 determines whether the user logging in presently is a non-log-out user who does not execute log-out processing for himself or herself. Then, if the user logging in presently is a non-log-out user, a forced log-out processing part 404 executes log-out processing when a previously registered identification processing is completed.