A car navigation system by which a user can easily grasp a drop-in target in the course of a route. In a summary road map displayed in a two- or one-window display representation, contents of a two-dimensional road map is properly selected and simplified, roads are made linear, roads connected to an intersection are made orthogonal so that the user can easily see it, the position of a vehicle is expressed by a mark, and even the running route is expressed with a predetermined color or the like. Accordingly, the system offers the user such a display form as able to easily refer to. When the user specifies a target at which the user wants to drop in, the drop-in target is displayed at a corresponding position on the summary road map in the form of a land mark.