When, during execution of a job, an operation/display control unit detects a job execution stop command given by an operation display unit, and receives a command to display a list of jobs in an execution standby state from the operation display unit, the operation/display control unit displays a job list screen on the operation display unit, without accepting an input of authentication information from the operation display unit and without passing authentication conducted by an authentication control unit. When the operation/display control unit accepts a command to delete a job in the execution standby state from the operation display unit, the operation/display control unit accepts an input of authentication information, and a job control unit executes deletion of the job in the execution standby state or change of setting of the job in the execution standby state after successfully passing authentication with the authentication control unit using the authentication information.