PURPOSE: To easily and accurately set a passage point by shifting a mark range to a detected crossing within the preset range of the point, when the mark range specifies a point outside the road of an established route.

CONSTITUTION: CPU 5 causes the processed result of data from distance and travel direction sensors 1 and 2, map data read out from a CD-ROM 3, the desired level of map information stored in a memory 6, a destination, a current position, a passage point specifying mark or the like to be respectively shown on a display 10. In this case, detailed maps necessary for setting a route are displayed in order on the basis of a map scaled for displaying the current position and the destination. Also, an input device 4 is operated, and an expected travel route is established on the roads of the maps for passing each crossing. Then, a mark range 60 is shifted to a crossing within the preset mark range to establish a travel route. When the mark range 60 specifies a point indicated by a mark 61 for other than roads, the range 60 is shifted to a detected crossing 62 within the preset range 70. As a result, a passage point can be easily and accurately established.