An image generation apparatus that generates an image notifying an occupant of a vehicle about a notification target located in a traveling direction of the vehicle, and outputs a virtual image of the image to a head-up display device that displays the virtual image while superimposing the virtual image on a foreground of the vehicle. The image generation apparatus includes: a target information acquisition part that obtains positional information and a moving direction of the notification target; an image generation part that generates a ripple image displayed by the head-up display device while superimposed on a road surface where the notification target is located when the target information acquisition part obtains at least one positional information; and a subject vehicle information acquisition part that obtains a traveling speed. The image generation part stops generation of the ripple image when the traveling speed exceeds a threshold speed specified beforehand.