A location support relating to a mobile station that can make use of multiple communication networks more efficiently. In an SUPL server of a location system, a judgment is made as to which of two communication networks is accessed by a mobile station based on information specifying the access point of the mobile station, with this access point being notified from the mobile station, whereby the information is then notified from the SUPL server to a location information management device. As a result, in the location information management device, requests to a communication network, which is not accessed by the mobile station, for location information for use in location of the mobile station are suppressed. This makes it possible for location support relating to a mobile station capable of using multiple communication networks to be carried out more efficiently.