PROBLEM TO BE SOLVED : To actualize real estate trading based on a market principle by improving inconvenience accompanying particularity of real estate objects or unevenly distributed information, thereby making smooth real estate trading and forming a real estate trading market.SOLUTION : Information on objects is accumulated in detail in a real estate object database 110, to which a dealer who is a seller and a purchase applicant user who is a buyer make access by means of a terminal 12. Information on desired requirements of the buyer is accumulated in a desired requirement database 130. The buyer can exactly find out a desired object by referring to statistical graphs, history data, indicative prices, and the like. Further, both the seller and the buyer can know variations in prices, negotiated prices, and the like, from the history data, data on the desired requirements, and the like, causing the prices of objects to be determined by both the sides.