PROBLEM TO BE SOLVED : To provide a property information regarding for a real estate, even for one in which there are residents staying there at the present and to realize application of living candidates.SOLUTION : A real estate information providing device is provided with a vacancy state DB 12 accumulating an information indicating respective vacancy states of real estate properties accumulated in property DB 11; a retrieval means 22 for searching the content of the property DB 11, corresponding to a search request from a customer terminal 4; an output means 23 for outputting searched result by the retrieval means 22 with an information indicating the vacancy state accumulated in the vacancy state DB 12 to the customer terminal 4; a temporary reservation means 25 for setting a temporary reservation to the real estate, corresponding to a request from the customer terminal 4, in the case where the vacancy state information indicates no vacancy; and a temporary reservation DB 16 accumulating a temporary reservation information indicating the result of the temporary reservation by the temporary reservation means 25. When the vacancy state information indicates with existence of a vacancy, this is informed to a customer by a vacancy informing means 26.