PURPOSE: To reduce the power consumption by storing minimum data required for normal input/output in a part for a non-contact communication means and storing the other data requiring a large capacity in a part for a contact communication means.

CONSTITUTION: A non-contact communication means 4 responds to a call signal transmitted from a transmitter-receiver of an external input/output management system, and ID data stored in a data storage part 2 is sent to the transmitter- receiver of the input/output management system through the non-contact communication means 4 and an antenna 3. Meanwhile, a memory whose capacity is normally larger than that of the data storage part 2 is used as a data storage part 15 for the contact communication means. The data storage part 15 is prepared to store data of individual information, etc., which cannot be stored in the data storage part 2. Consequently, time data storage part 15 is not used for normal input/output, and an ID card 1 is inserted to the connector of an external device to read/write data from/n the data storage part 15 through a CPU 14 and a terminal 16 if it is necessary.