To make it possible to exchange electronic money(EM) with normal cash and to allow the EM from being generally accepted by updating respective transaction logs by 1st and 2nd transaction money modules(MMs) to end a cession, and when the transaction is failed, recovering the states of respective MMs through an aborting means.

The transaction MMs 4 are formed as an illegal change preventing state and a cryptograhic security cession is set up between the 1st and 2nd transaction MMs 4. The 1st MM 4 sends a 1st message including a transfer amount to the 2nd MM 4 through the cession to urge a 2nd subscriber to check the transfer amount. The 2nd MM 4 sends a receiving message to the 1st MM 4 through the cession and the 1st MM 4 transfers an electronic symbol, of money to the 2nd MM through the cession. The 1st and 2nd MMs 4 update respective transaction logs to end the cession, and when the transaction is failed, respective MMs 4 recover their states through the aborting means.