PURPOSE: To efficiently utilize plural kinds of cards by recording the information for showing the memory capacity of the card onto the IC card, in the IC card having a fixed information recording area and a variable information recording area.

CONSTITUTION: IC cards A1, B2 have a fixed information recording area and a variable information recording area, respectively, and for instance, the memory capacity of the card A1 is larger than that of B2. In order that the cards having each different memory capacity in this way can be mixed and used in a bank on-line system, memory capacity information 3 for showing the memory capacity of the card concerned in recorded in a part of the fixed information recording area. This card is read by a card reader, and read information is sent to a central processor through a terminal equipment, etc. The central processor recognizes the memory capacity of the IC card of a service object, by the memory capacity information in the information which has been sent, and executes a processing corresponding to the memory ability of the IC card concerned.