To enhance power saving, and also prevent AM noise, in an electrical actuator driver.

A large-capacity capacitor 6 is connected to a power line 2a connected from a power unit 2 to a control unit 1, and a motor 6 is driven by controlling a drive element FET 1b by mean of a CPU 1a, according to the operation signal from a switch box 5 at hand. Accordingly, the power unit can be made into low capacity, by using a capacitor as a power source, thus the downsizing of the device can be enhanced, and additionally not only can AM noise be reduced, but also the reduction in power and the adoption of a countermeasure to higher harmonic currents become easy, because there is no need for letting a current flow more than it, when the charge is completed at waiting, and also the safety rises by power output being limited automatically.