Disclosed is a map data creating device including an average travel speed calculating unit for calculating an average travel speed in each link included in searched route data showing a route which is searched for by a route searching unit according to information which is included in map data acquired from a map database and which is assigned to the link, a control unit for dividing the route which is searched for by the route searching unit into sub-routes according to the average travel speed from the average travel speed calculating unit to acquire map data about a map having a scale according to an average travel speed assigned to each of the sub-routes into which the route is divided from the map database, and a searched route data storage unit for storing the map data acquired by the control unit while bringing the map data into correspondence with the sub-route.