An image data processing system, comprises first and second storing sections; an administrative control section to administrate the image data stored in the first storing section or the reduced image data stored in the second storing section; an authenticating section to conduct an authenticating process for an access from a customer terminal on a network; the administrative control section making it possible for the customer to peruse the reduced image data when the authenticating section is accessed with the provisional ID and the administrative control section capable of conducting a receiving process for a member ID; and the administrative control section making it possible to receive an operation for at least one of the reduced image data in the second storing section and the image data stored in the first storing section.