PROBLEM TO BE SOLVED : To provide a real estate item retrieving system capable of easily retrieving a house, and automatically calculating a purchase plan by inputting item information to an electronic map.SOLUTION : This real estate Navi system 1 capable of retrieving real estate items on a net is provided with an information registering means having a data base for registering item information from a real estate agent in a data base, an information inputting means capable of inputting information to the data base, an information editing means capable of editing the information of the data base, and an information outputting means capable of outputting information edited by the information editing means. This real estate item retrieving system is also provided with a house retrieving means capable of retrieving item information desired by a customer from the information of the data base, and a purchase planning means capable of making a purchase plan at the time of purchasing the item.