<p>There are provided a displaying means arranged at a position that can be looked at from a driver's seat of a vehicle, an image picking-up means for picking up an image of a rear portion of the vehicle containing at least a part of a hitch that is provided to the rear portion of the vehicle, and an image processing means for causing the displaying means to display a synthesized image that is obtained by image-processing an image picked up by the image picking-up means, wherein a hitch image 35a of own vehicle in addition to an image 41a of a trailed vehicle and an image 42a of the coupler are displayed on a screen of the displaying means. As a result, the relative positional relationship between the hitch and the destination coupler can be checked on the screen and thus the hitch coupling operation can be facilitated. <IMAGE></p>
