A navigation device and the like capable of harmonizing a navigation route for guiding a mobile body set on the basis of a support route search result by a navigation server and a navigation route for also guiding the mobile body set independently of the navigation route, from a view point of guiding the mobile body smoothly. In the case where the second navigation route r2 is set in the condition where the first navigation route r1 is set, the second navigation route r2 is set and output so as to include a part dr1 of the first navigation route r1 which takes a position departing from the current position pt of the automobile 2 by a first distance d1. Therefore, even in the case where the second navigation route r2 is set and output at the navigation device 200 during the time when the automobile 2 is traveling according to the first navigation route r1 output at the navigation device 200, it is possible to guide the automobile 2 according to the original first navigation route r1 until the position departing from the current position pt of the automobile 2 by the first distance d1. Therefore, it becomes possible to guide the automobile 2 smoothly to the destination position p2, without forcing the automobile 2 to perform abrupt behavior change.