PROBLEM TO BE SOLVED : To construct a system for retrieving real estate property for sale at present, while recognizing it as a three-dimensional virtual room and to reform the form of conventional real estate selling. SOLUTION : A first data base storing three-dimensional shape data of the real estate property and a second data base storing interior information of the real estate property as three-dimensional shape data are arranged so that they can be referred to through Internet. A browser provided with a first display part displaying the inner part of the real estate as virtual space based on three- dimensional shape data which is read from the first and second data bases, and a second display part displaying an operation menu, by which the purchaser of the real estate operates a viewpoint displaying virtual space is registered in a server, so that it can be obtained via the Internet.