PROBLEM TO BE SOLVED : site visit the site at which the real estate in the electronic data base as estate information can be updated. SOLUTION : tablet 11 on the display of the tablet 11 by including the position of a GPS function map is displayed. On the map is displayed on a display of the predetermined position of the position of the estate of real estate touching the estate information is displayed on the display. By changing the position of the real estate to update the information on a display. Therefore, as in the conventional example recorded by the recording means such as notebook once again recorded information is inputted to the computer is not required, and is easily estate information database. Selected drawing : fig. 1