A servo control apparatus according to the present invention includes a speed command generator; a torque command generator; a speed detector; a speed control loop; a speed control loop gain setting unit; at least one filter for filtering a specific band of a torque command value; a sinusoidal disturbance input unit for performing a sinusoidal sweep on the speed control loop; a frequency characteristics calculator for estimating the gain and phase of speed control loop input and output signals; a resonance frequency detector; a filter adjuster for adjusting the filter in accordance with a resonance frequency; a gain adjuster; a sequence controller for online and automatically performing the detection of the resonance frequency, the adjustment of the speed control loop gain, and the adjustment of the filter; and an adjustment state display unit. The adjustment state display unit displays a stage and progress in the adjustment by the sequence controller.