The steering angles of front wheels 3f and rear wheels 3r of a vehicle 1 can be respectively controlled by a front wheel steering angle control actuator 35 and a rear wheel steering angle control actuator 44. If a steering wheel 20 is operated in a turning direction of the vehicle 1 while the vehicle 1 is traveling in a straight line, then a controller 60 changes the steering angle of the front wheels 3f to approach to a steering angle specified on the basis of an operation amount after the steering wheel 20 is operated, and also controls the front wheel steering angle control actuator 35 and the rear wheel steering angle control actuator 44 to change the steering angles of the rear wheels 3r to the opposite direction of the turning direction of the vehicle 1 immediately after the steering wheel 20 is operated.