An actuating device for hydraulically actuating at least one setting element comprising a pump, which has an electric pump drive, with reversible pumping direction, at least one double-acting piston-cylinder arrangement, which is connected therewith and the piston of which is operatively connected with the setting element, and a hydraulic fluid reservoir from which the hydraulic fluid can be pumped to the piston-cylinder arrangement in order to hydraulically load the piston thereof for a setting element movement depending on pumping direction on one (effective surface 22) or other (effective surface 24) side. In this connection, the piston-cylinder arrangement is functionally associated with a detent device with a blocking element, which is spring-biased into a blocking position preventing setting element movement and is movable by an electrically activatable actuator from the blocking position into a release position permitting setting element movement.