PROBLEM TO BE SOLVED : To provide real estate management which makes it possible to accurately grasp the use state, performance, etc., of dispersed real estate items without increasing the load on respective branch offices.SOLUTION : Databases 10 and 11 of drawing data and property data regarding information on the real estate items are arranged at a general management department 1. When alteration information is sent from a terminal of a branch office 3 to the general management department 1, data in the databases 10 and 11 are updated. The update is carried out by a support institution 19.