Detection of frauds and circulation of money can be managed while no special apparatus is required, electronic cash can be securely utilized, and personal information and information on individual's purchase are not unnecessarily known. An account management unit 45 stores an amount of money utilized by a user based on information for identifying the user and previously deposited funds. A clearing unit 55 instructs a payment institution to make a settlement. The user management unit 35 manages the information for identifying the user, and an account number of the user in the payment institution encrypted with a public key of a settlement processing apparatus. A communication unit 37 instructs an account management apparatus to change the balance of the previously deposited funds of the user stored therein based on the information for identifying the user, and instructs the settlement apparatus to execute a settlement based on the account number in the payment institution.