A multi-function apparatus having a wider variety of uses and easily employed when carrying a USB cable only without having a power source cord. The apparatus includes means for detecting a connection between the USB interface and the PC, means for detecting a connection to the power line, and control means for selecting a function depending on a detected state of the connection between the USB interface and PC and a detected state of the connection to the AC power line. All the functions in the multi-function apparatus are operable in a connected state of the AC power line to the AC power source, while even in an unconnected state of the AC power line to the AC power source, if the USB interface is connected to the PC, a possible operation is enabled using electric power of 5 V at 500 mA supplied from the PC.