A mobile terminal such as a portable telephone accesses a map database server connected to the Internet, and positional data, destination, etc. acquired from a GPS receiver mounted on the mobile terminal are cataloged in the map database server. The results of a search for a route, route indication, etc. are received from the map database server in the form of a voice, a simplified map, or both a voice and a simplified map and are indicated on a display of the mobile terminal. By virtue of the above construction, a navigation system can be realized which can eliminate the need to update map data, is low in price, has no need to provide an installation space, has low power consumption, and can be simply and easily utilized.