Data communication method and data communication system

A first server in a system includes confirmation requesting unit 110 that receives an authentication request from a predetermined apparatus 400 coupled through a public line and that sends a user confirmation request to a second server in the case where user authentication is successful. A second server includes a user facility identifying unit 210 that receives the user confirmation request from the first server and identifies location information of the user facility of the user and a confirmation result notifying unit 211 that receives a utilization request from a measuring apparatus linked through a dedicated line and identifies disposition location information of the measuring apparatus and that sends a notification of success of user confirmation including the identification information of the user to the first server 100 if the disposition location information of the measuring apparatus is identical to the user facility location information.