An image processing apparatus includes an image processing unit, a switch which receives an input of a power supply-off command, a first controller which supplies power to at least the image processing unit, and a second controller. The first controller detects an input to the switch, and when an input to the switch is detected at a state where the apparatus is supplied with power, performs power supply-off processing of switching the apparatus to a state where the apparatus is not supplied with power. The second controller detects whether the first controller is at an abnormal state, and when it is detected the first controller is at the abnormal state, performs vicarious processing of performing at least a part of the power supply-off processing of the first controller.