In an image forming apparatus, a reservation managing unit receives a reservation request from a mobile terminal device of a user, and registers reservation information. The reservation information indicates (a) a usage time zone specified by the received reservation request and (b) the mobile terminal device. The operation restriction unit changes an operation control mode from an operation permission mode to an operation prohibition mode if (a) the mobile terminal device detected by a terminal detecting unit is a mobile terminal device of a reserving user who reserved as the usage time zone a current or a next time zone and (b) there are no currently using users. The operation permission mode is a status where an operation of an unspecified user can be received, and the operation prohibition mode is a status where a user operation is prohibited until a release operation of the reserving user.