Thus, owing to viewing the virtual vehicle indicated by the virtual image 812, 812′ stopped on the planned parallel parking space indicated by the symbol image 77, 77′, the occupant can confirm in advance whether there is a sufficient space necessary for the own vehicle to perform parallel parking on the road shoulder 71, 71′. Further, the occupant can confirm in advance whether no obstacle exists on the travel course from heading-back at the symbol image 79, 79′ to the planned parallel parking space.