A navigation apparatus equipped in a movable body, is provided with: a position measuring device for measuring a self-position of the movable body; an input device for inputting a destination position; a displaying device for displaying a present position, which is measured by the position measuring device, and an optimum course from the present position to the destination position; a memory device for storing map information including course data beforehand; and an optimum course searching device coupled to the memory device and the displaying device, for evaluating various courses from the present position to the destination position by use of the map information stored in the memory device, and searching the optimum course by selecting a course, which evaluation is the best one among the evaluated various courses, as the optimum course.