A navigation apparatus, which is carried on a vehicle, computes the present positions of the vehicle by using the data collected by various types of sensors, and visually presents the computed present positions on a display. An absolute position data membory stores the surveyed data of the previously surveyed reference points in correspondence with the reference points. A key input device generates a passing signal indicating that the vehicle has actually passed on the the reference points. is response to the operationm of a matching key. When receiving the passing signal, a CPU compares the survey data of the reference points stored in the map data storing means with the present position data calculated by using the data derived from the sensors, selects the surveyed data of a reference point of which surveyed data provides the smallest difference between the reference point and the present position data, and corrects the present position data so that is becomes the selected surveyed data.