Front left and right cameras are arranged at front left and right end parts, respectively, of a vehicle to capture a corresponding peripheral image around the vehicle. A control circuit controls a displaying operation of a display device based on a sensed current position of the vehicle and road map information in such a manner that when the vehicle approaches a junction where a current road, along which the vehicle currently travels, joins an encountering road, the peripheral images of front left and right cameras showing a corresponding view of the encountering road are displayed on the display device upon satisfaction of predetermined conditions.