An image-forming apparatus for forming an image by heating a medium, the image-forming apparatus includes a connector connectable to a heating unit that heats the medium; a conmmercial power supply that generates power to be supplied to the heating unit; a switch system, provided between the heating unit and the conmmercial power supply, that switches the supply of the power to the heating unit on or off; and a switch control unit that controls the switch system based on the heating unit type.