The control apparatus includes an acquisition unit, an air volume setting unit, and an air blow control unit. The air volume setting unit sets a volume of air to be blown toward the plurality of sheets from a separation blower based on the information on the processing job acquired by the acquisition unit or by manipulation of a user. When the air volume is changed from a first air volume to a second air volume different from the first air volume by the user, the air volume setting unit maintains the air volume as the second air volume, irrespective of the information on the processing job acquired by the acquisition unit, until the air volume is changed from the second air volume to an air volume different from the second air volume by the user.