PURPOSE: To make a system which is excellent in response by shortening a processing time on a master side.

CONSTITUTION: An enquiry code is always transmitted from a reader 1. In an IC card 2, all data including function codes is written in the EEPROM 2-6. When the IC card enters in electromagnetic field formed by the reader 1, the enquiry code is received and it is given to a control logic 2-5. The control logic 2-5 collates the enquiry code and an intrinsic code, and returns the function codes when both of them coincide. The reader 1 receives the function codes from the IC card 2, analyzes them and requests the IC card 2 to transmit the necessary data.