A navigation apparatus includes a map database that records map data in a fixed storage medium, a map data read section for reading map data from the map database, and a navigation section for detecting the location of local apparatus, calculating a route to a destination specified by the user, and giving guidance to the destination according to the route, a map information acquisition section for acquiring map information from outside the navigation apparatus, and a map information update section for updating the map database with the map information acquired by the map information acquisition section. The navigation section includes an emphasis display section that displays updated data detected in a difference data detecting section, in an emphasized way, and an emphasis voice guidance section that emphasizes the data detected in the difference data detecting section.