PROBLEM TO BE SOLVED : To provide a server apparatus, a method and a program for intermediary for trade of real estate capable of providing an intermediary service for a trade of real estate efficiently and safely. SOLUTION : In a system for intermediary for trade of real estate, property information is acquired from a seller desiring a sell-off of a real estate via a home page for intermediary of real estate opened on the Internet by a main office. A research on property regarding the property information is requested to a member agent as a local real estate agent. Sales conditions such as a sales price are decided based on a report from the agent while discussing with the seller. When desired property is found on the home page, a request for an observation can be submitted via the home page to the office. When receiving the request, the office requests the agent to provide a guide on the site for a buyer. Then, the office concludes a contract by adjusting requests of the seller and the buyer, and requests the agent to register the real estate.