A printer includes an authenticator that authenticates a login of a user, a prohibited job memory that stores a prohibition information list, a prohibition list register that loads job information on a print job from a storage medium installed in the printer and stores the job information in the prohibited job memory as the prohibition information list in [1] a case where a preset time has elapsed from the user's last operation or [2] a case where the storage medium is still installed in the printer at a user's logoff request, and a controller. In loading a print job from a storage medium installed in the printer, the controller prohibits a print process of the print job loaded from the storage medium when job information of the print job loaded from the storage medium corresponds with the job information contained in the prohibition information list.