An objective of the present invention is to provide a navigation device and method which mitigate user annoyance associated with boundary guidance, and prevent the user from misidentifying a region which the user is moving through. A navigation device according to the present invention comprises: a prefectural border detection means (9) as a boundary detection means for searching on the map in the forward direction of travel of a vehicle (100) as a moving body and detecting a plurality of boundaries (prefectural borders) on the map; and a guidance means (12) as a boundary guidance means for providing comprehensive guidance to a user about the plurality of boundaries (prefectural borders) which are present in a prescribed range, on the basis of the results of the detection in the prefectural border detection means (9).