When a search condition is supplied, a road name drawing process acquires a target road name corresponding to a search target spot. The road name drawing process searches a plurality of display map datasets for character data corresponding to a plurality of scales and acquires a scale for a display map dataset whose character data contains the corresponding target road name. The road name drawing process performs a map drawing process using that scale. Namely, the process draws a map containing the search target spot so as to display the target road name corresponding to the search target spot. For this purpose, the process previously searches a plurality of display map datasets for character data and uses the display map dataset whose scale allows the character data to contain the target road name.