An image forming apparatus comprising: an image forming unit adapted to form an image; a power supply adapted to supply operating power for the image forming apparatus; a switching circuit unit adapted to switch to selectively supply the operating power; a memory unit adapted to store information about power status of the switching circuit unit; a controller adapted to output a power control signal to control a switching operation of the switching circuit unit in accordance with the information about the power status stored in the memory unit if power is abnormally shut off and then supplied again from the power supply to the switching circuit unit; and. a key input unit adapted to receive a user input related to supply of the operating power, characterised in that: the switching circuit unit comprises a first switch (PW_SW) adapted to be turned on in response to the user input into the key input unit and a second switch adapted to be turned on/off in response to the power control signal of the controller, and the controller is adapted, if power is supplied to the switching circuit unit without a user input to the first switch (PW_SW), to read the information about the power status from the memory unit and output the power control signal for turning on/off the second switch to match with the read information about the power status. an image forming unit adapted to form an image; a power supply adapted to supply operating power for the image forming apparatus; a switching circuit unit adapted to switch to selectively supply the operating power; a memory unit adapted to store information about power status of the switching circuit unit; a controller adapted to output a power control signal to control a switching operation of the switching circuit unit in accordance with the information about the power status stored in the memory unit if power is abnormally shut off and then supplied again from the power supply to the switching circuit unit; and. a key input unit adapted to receive a user input related to supply of the operating power, characterised in that: the switching circuit unit comprises a first switch (PW_SW) adapted to be turned on in response to the user input into the key input unit and a second switch adapted to be turned on/off in response to the power control signal of the controller, and the controller is adapted, if power is supplied to the switching circuit unit without a user input to the first switch (PW_SW), to read the information about the power status from the memory unit and output the power control signal for turning on/off the second switch to match with the read information about the power status. the switching circuit unit comprises a first switch (PW_SW) adapted to be turned on in response to the user input into the key input unit and a second switch adapted to be turned on/off in response to the power control signal of the controller, and the controller is adapted, if power is supplied to the switching circuit unit without a user input to the first switch (PW_SW), to read the information about the power status from the memory unit and output the power control signal for turning on/off the second switch to match with the read information about the power status.