A navigation apparatus is disclosed comprising update functions to update
nationwide updated version map data using route-specific update data, and
to update the nationwide updated version map data to the next nationwide
updated version map data using nationwide update data. A map update
processing portion of this navigation apparatus performs updates of map
data in the background of navigation control, gives priority to update
processing using the route-specific update data over update processing
using the nationwide update data, and, if map files to be updated using
route-specific update files included in the route-specific update data
have not been updated using the nationwide update data, performs updates
using the nationwide update data, and then performs updates using
route-specific update files.