To solve the problem wherein, in a conventional method of searching recommended route, when an operator designates a road desired to pass, a search cost for the designated road is changed and re-search is performed, and therefor a pertinent road is required to be designated on a displayed map in order to set the search cost, and the operator is required to perform a troublesome operation in order to achieve it actually.

A branch point or a road used as a base point of edition is selected by extracting main branch points or roads from route information of a recommended route searched for by a plurality of set search conditions, and the selected spots and the recommended route between the spots are re-searched for by the plurality of search conditions, and each route information of the recommended route re-searched for and the recommended route searched for beforehand is edited into one route information, to thereby generate simply the optimum recommended route.