An image processor comprising: a user information storage unit for storing information of a plurality of users; a plurality of different user information input units for inputting user information; a user information matching unit for determining whether or not user information inputted by said respective user information input units matches any of the user information registered in said user information storage unit; a job processing unit for executing jobs instructed by a user, whose user information is determined to match any of the registered user information by said user information matching unit; and a job processing control unit for restricting jobs that are processed by said job processing unit, depending on which user information input unit is used.