To use the same onboard apparatus and navigation system in many kinds of vehicles. A table in which manufacturers and vehicle types are connected with designs and functions has been previously stored in a navigation system module 21. The navigation system module 21 itself sends the center controller 11 a query about vehicle information (the country that manufactured, manufacturer, vehicle type, using country, manufacturing number), recognizes the vehicle information supplied from the center controller 11, and automatically sets the screen design, function, etc., suitable to the vehicle on which the onboard apparatus is mounted.