A navigation system (500) is provided with: a navigation apparatus (510); a server apparatus (520) and a route information transmittance apparatus (530), which are inter-communicable via a communication network (540). The route information transmittance apparatus is provided with: an input device (531) for inputting route search information indicating an instruction of a route search; and a transmittance device (532) for transmitting the route search information to the server apparatus. The server apparatus is provided with: a server side communication device (521) for receiving the route search information; an authentication device (522) for authenticating whether or not the route search information is available; and a search device (523) for performing the route search on the basis of the authenticated route search information. The server side communication device transmits search result information indicating a searched route to the navigation apparatus. The navigation apparatus is provided with: a terminal side communication device (511) for receiving the search result information; and a route guidance device (512) for performing a route guidance on the basis of the search result information.