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, and update the map information based on the one or more pieces of difference update information. The systems, methods, and programs obtain total update information used for updating an entirety of the memory to a new piece of map information, update the map information based on the total update information, compare a version of the total update information used in the total update with each of versions of the one or more pieces of difference update information stored in the memory, extract any of the one or more pieces of difference update information judged to be newer and update the map information based on the difference update information.