The invention relates to an actuating device for moving a flap of a piece of furniture, comprising, at least one actuating arm for moving said flap, a base member on which said actuating arm is pivotally arranged, a spring device being able to act upon said actuating arm, wherein an assembly securing device for the vacant actuating arm, which has not yet been fitted with a flap is provided, and said assembly securing device comprises a braking device which limits the opening speed of said vacant actuating arm.