The present invention provides a memory card equipped with an interface controller connected to external connecting terminals, a memory connected to the interface controller, and a security controller connected to the interface controller. A second external connecting terminal capable of supplying an operating power supply to the security controller is provided aside from a first external connecting terminal which supplies an operating power supply to the interface controller and the memory. An interface unit of the interface controller connected to the security controller receives the operating power supply from the second external connecting terminal and thereby enables a stop of the supply of the operating power supply from the first external connecting terminal. Even if the supply of the operating power supply to the interface controller is cut off, the output of the interface unit is not brought to an indefinite state.