In a navigation apparatus having: a base unit (10) that is fastenable to a vehicle and is equipped with at least a microcomputer; and a front panel unit (14) that is attachable to and detachable from the base unit and is equipped with at least a display (14b) displaying map data and a microcomputer performing a navigation function to indicate a determined location of the vehicle on the map data, it is configured such that a front surface of the front panel unit is made same size as a mating face of the base unit; and the display occupies 70% or greater of length of the front panel unit in a lateral direction. With this, the front panel unit including the microcomputer for performing navigation functions can be configured to be attachable/detachable to/from the base unit to enhance ease of use, and the size (area) of the display formed in the front panel unit can be increased to improve viewability.