A route search device capable of searching for a route with the lowest energy cost at a high speed even if the distance between start and end points is long. The route search device includes: a long distance search attribute calculation section for calculating, as an attribute of one long distance search link, the sum of upslope elevation differences of a plurality of short distance search links and the sum of downslope elevation differences of the short distance search links corresponding to the one long distance search link; and a link cost calculation section for calculating, based on the attribute of the long distance search link and vehicle characteristics, a link cost that is an energy consumption at a time when a vehicle travels in the long distance search link.