In order to prevent without fail the abuse of certificate information which are exchanged on a network, an orderer inputs the certificate information to a certificate terminal when placing an order for a commodity, the certificate terminal encrypts the certificate information to send it to an order receiver and holds the certificate information and a decryption key. A deliveryman, at the time of commodity delivery, inputs the encrypted certificate information to the certificate terminal, and the orderer inputs data of terminal certification to the certificate terminal. The certificate terminal, when it certifies by the data that the orderer is the valid owner of the certificate terminal, decrypts the encrypted certificate information input by the deliveryman, by the decryption key in the certificate terminal, verifies decrypted certificate information with the certificate information in the certificate terminal, and the deliveryman hands over the commodity to the orderer when the certificate information match.