When the amount of a loan of the user of an IC card is written to a personal information storage provided in a center and when the IC card is inserted into the slot of an electronic purse terminal at the time of a current transaction, the amount of the loan stored in the personal information storage is cleared and this loan is paid. The balance stored in the sum information storage of the IC card is updated by this payment and is stored as the current balance in the sum information storage. If the balance is more than the charge for a transaction, the transaction is carried out and if the balance is less than the charge for the transaction, the transaction is performed by obtaining a new loan. The amount of this new loan is stored in the personal information storage.