Map data product and map data processing apparatus

A data product that can be read by a computer or a map data processing apparatus, contains map data including map-related information related to a map. And the map-related information includes a compilation of a plurality of information elements of a single type; the map-related information can be updated in units of the individual information elements at the map data processing apparatus; and the map-related information includes management information used to manage the map-related information, which is also updated when the map-related information is updated in units of the individual information elements.