PURPOSE: To prevent the physical destruction of an IC card and the destruction of a storage content from occurring by supplying a current to the IC card only when it is operated and stopping the supply of the current when it is not operated by switching the supply or the stoppage of the current to the IC card corresponding to the operating state of the IC card by a current supply switching means.

CONSTITUTION: An address signal and a data signal which instruct the switching of the on-state of a transistor 2 are outputted from a microcomputer 1, and are sent to an output port 6, and the transistor 2 is switched to the on-state. Thereby, the current is supplied to the IC card, and also, a light emitting diode 3 is lit. When a CS signal is sent from a decoder 7 to a memory card by the instruction of the microcomputer 1, the microcomputer 1 can make access the memory card via an address bus, a data bus, and a control bus. When access is completed, the supply of the current to the IC card is stopped, and the light emitting diode 3 is put off. Thereby, it is possible to surely and easily prevent the physical destruction of the IC card and the destruction of the storage content from occurring.