A control device of a servomotor includes a current control loop selecting unit configured to select a first current control loop or a second current control loop having a response speed slower than that of the first current control loop, as a current control loop for controlling a current flowing through the servomotor; a filter configured to attenuate an input or an output of the first current control loop or the second current control loop selected by the current control loop selecting unit in accordance with a set attenuation ratio in a specific frequency range; and a filter attenuation ratio setting unit configured to set, as the attenuation ratio of the filter, a first attenuation ratio when the first current control loop is selected by the current control loop selecting unit, and a second attenuation ratio smaller than the first attenuation ratio when the second current control loop is selected.