A sliding mode control apparatus. When displacing a controlled object to which an urging force is applied by an elastic member from one displacement end to the other displacement end, the control apparatus sets a switching hyperplane and controls the controlled object by using a sliding mode control in such a manner that a state quantity of the controlled object is converged on the switching hyperplane. In the sliding mode control, the control apparatus switches an operation mode for controlling the controlled object when the controlled object passes an operation switching point. The control apparatus detects disturbance in the sliding mode control and a change with time of the elastic member, and changes the operation switching point in accordance with both of the detected disturbance and the detected change with time.