PROBLEM TO BE SOLVED : To efficiently find a property coinciding with various desired purchase conditions.SOLUTION : By a customer condition analyzing means 11, the desired purchase conditions and customer information written by a customer in a natural language is analyzed, and by a retrieval condition setting means 12 the retrieval conditions for the property is set. A candidate property outline extracting means 13 is used to access a plurality of property databases 4 according to the retrieval conditions to extract a plurality of candidate properties. A candidate property detail retrieving means 17 is used to narrow down the candidate properties according to a loan payment condition, a commuting time condition and an ambient surrounding condition by referring to the customer information of a customer information storing means 14, the financial information of a financial information database 15 and the map data of a map database 16, and the candidate property is decided by a candidate property deciding means 18.