The invention solves the inconvenience that a customer would experience when his/her electronic wallet was lost or broken down. A backup condition testing means tests predefined backup conditions to determine whether to make a backup, when an electronic wallet device communicates with any other device to transfer monetary data. When the backup condition testing means has determined to make a backup, a backup data sending means sends a predetermined set of backup data collected from the electronic wallet device. A backup data management means receives the backup data from the backup data sending means and saves the received data into its backup database. In this way, the proposed system automatically saves backup data of the electronic wallet device when any backup condition is met. This mechanism permits the customer to have an alternative electronic wallet device to be promptly issued when his/her electronic wallet device is lost.