Map updating systems, methods, and programs that store map information, including one or more pieces of difference update information, obtain the one or more pieces of difference update information used for updating a part of the map information to a new piece of map information, update the map information based on the one or more pieces of difference update information, and obtain total update information used for updating an entirety of the map information to a new piece of map information. The systems, methods, and programs perform a total update on the map information based on the total update information, update the map information on which the total update has been performed based on the one or more pieces of difference update information, and delete the one or more pieces of difference update information from the memory after the map information is updated by the re-updating means.