A control apparatus of the present invention comprising a control unit outputting a control signal controlling a servo motor and suppressing natural vibration of a controlled object including a motor and a machine driven by the motor while controlling the controlled object, comprising a frequency analysis unit analyzing a frequency component included in a torque command, an analysis control unit controlling the start or stopping of the frequency analysis unit, a detection unit detecting a natural frequency of the controlled object from an analysis result of the frequency analysis unit, a-band rejection filter receiving as input the torque command, stripping the command of the natural frequency component, and outputting the resultant command to the motor through a current control unit and servo amplifier, and a filter characteristic setting unit setting the frequency to be stripped at the filter based on the natural frequency detected by the detection unit.