A camera for taking a state behind a vehicle is installed in a position laterally shifted from the rear center of the vehicle. An image processing unit generates a rear image from a camera image by shifting merely a rectangular area of the camera image so that a vertical center line thereof can substantially accord with the center line along the lengthwise direction of the vehicle. Furthermore, processing for correcting lens distortion may be performed. As a result, when the vehicle is moved straight backward, an object present on the center line of the vehicle moves vertically in substantially the center of the screen, so that a user can be prevented from having an odd feeling to see the image.