The invention relates to an actuator, including at least one pivotably supported actuating arm for moving a furniture flap. The actuating arm is or can be acted on by a spring device, and a retaining clip is proposed for the empty actuating arm on which no furniture flap is mounted yet. The retaining clip prevents accidental opening or deflecting of the empty actuating arm and for this purpose includes a brake or detent device which can be moved by a shaft (R). A transmission gear is provided by which the pivot speed of the actuating arm can be geared to a higher rotational speed of the shaft (R) at least over a region of the pivot travel of the actuating arm in the open direction.