An electrostatic actuator and a method of driving the same are provided. The actuator controls the displacement of a target object by adjusting a voltage between fixed comb electrodes and a moving comb electrode. The actuator includes an actuator control signal generator generating an actuator control signal by pulse-width modulating an actuator driving signal and a carrier signal; and an actuator unit including the fixed comb electrodes and the moving comb electrode and adjusting the voltage according to the actuator control signal. Accordingly, the displacement can be easily controlled using the pulse-width-modulated actuator driving signal even when both the voltage of the actuator driving signal and the frequency of the carrier signal are high.