The turning amount of a turning unit is controlled according to the steering amount of a steering unit mechanically uncoupled from the turning unit. A steering reaction force characteristic in which the larger the self-aligning torque, the larger the steering reaction force is set on coordinates with the self-aligning torque and the steering reaction force as coordinate axes. When the steering reaction force corresponding to the self-aligning torque is applied to the steering unit based on the steering reaction force characteristic, the steering reaction force characteristic is offset on the coordinates in such a direction that the closer the lateral position of an own vehicle to a white line, the larger the absolute value of the steering reaction force.