An embodiment of the present invention allows for application of an assist torque or reaction torque which causes a driver to feel less discomfort. An ECU (600) includes a control variable calculating section (611) configured to calculate a control variable for controlling a magnitude of the assist torque or reaction torque, with reference to a steering torque applied to a steering member (410); and a control variable correcting section (612) configured to correct the control variable calculated by the control variable calculating section, with reference to a roll rate of a vehicle body, a steering angle of the steering member, and a steering angle speed of the steering member.