PROBLEM TO BE SOLVED : To easily perform personal transaction of real estate without involving a real estate agent.SOLUTION : The complete personal transaction of the real estate can be performed by connecting provider terminals 1-1 1-2, to be used by a first user who desires sale and lease of the real estate, user terminals 2-1, 2-2 to be used by a second user who desires purchase and lease of the real estate and a brokerage server 3 to perform real estate transaction between the first and second users by a network 4, processing sale information, lease information, purchase information, lease information of properties registered from the provider terminals 1 and the user terminals 2, opening them on the network 4 and processing a role required for the real estate agent on the network 4 by the brokerage server 3.