A control apparatus includes a display unit, a storing unit, a determining unit, and a control unit. The display unit displays a job. The storing unit stores attribute information about a sheet to be accommodated in a sheet holding unit. The determining unit determines whether attribute information about a sheet to be used in the job corresponds to attribute information about the sheet stored in the storing unit. The control unit controls the determining unit, wherein, after determination processing by the determining unit has been completed. the control unit controls the determining unit to further perform determination processing in response to a change of the attribute information about the sheet stored in the storing unit, or in response to a change of the attribute information about the sheet to be used in the job.