An image forming apparatus includes a fixing device and an image forming apparatus body. The fixing device includes a pressure unit, a heating unit, a pressure adjuster that adjusts a pressure between the pressure unit and the heating unit, and a fixing-device-side connecting device. The image forming apparatus body to which the fixing device is detachably attached includes an electrical power unit, a drive device to which electrical power is supplied from the electrical power unit so as to drive the pressure adjuster, and a body-side connecting device connected to the electrical power unit. When the fixing device is detached from the image forming apparatus body, the body-side connecting device and the fixing-device-side connecting device are disconnected from each other and electrical power supply to the drive device is interrupted.