Thus, owing to that the virtual vehicle indicated by the virtual image 85, 85′ virtually performs parking on each of the first and second display devices 3, 4, the occupant can confirm in advance whether the parking space 82, 82′ has a sufficient space necessary for the own vehicle to perform parking thereat. Further, the occupant can confirm in advance whether no obstacle exists on the travel course from heading-back at the symbol image 84, 84′ to the parking space 82, 82′.