It is characterized by including a storage section (214) in which location information of a base station (30) that performs wireless communication with a wireless terminal (40) and base station identification information uniquely assigned to each base station are registered in association with each other, a receiving section for receiving signal strength information in which a signal strength of a signal received by the wireless terminal from each base station or information obtained from the signal strength and the base station identification information of the base station that transmitted the signal are associated with each other, a registration judging section (222) judging, by referring to the base station identification information registered in the storage section, whether or not the base station identification information included in the signal strength information received by the receiving section is registered in the storage section in association with the location information, and a registering section (226) for registering in the storage section in association with each other the base station identification information judged by the registration judging section as not registered in the storage section and predetermined location information dependent on the location of the wireless terminal.