A system can certify that electronic data has been notified and published on a network. The system comprise an information providing server having a published information storing function and a published information bulletin function, and a viewing-access-log recording server having a data trapping function and a data storing function. The system is widely used as a service certifying that various information from a company has been notified and published as electronic data on the communication network, or that various technical information has been published as electronic data on the communication network to be public knowledge.