Hydraulic actuating apparatus, which comprises a master cylinder (2, 20), a liquid vessel connected to the master cylinder (2, 20), a working cylinder (3, 30), and a pedal (1, 10) connected to the thrust rod of the master cylinder (2, 20); wherein said hydraulic actuating apparatus furthermore comprises an automatic hydraulic drive device (5, 40, 430), and the automatic hydraulic drive device (5, 40) comprises: an oil cylinder, wherein, on the oil cylinder, a first and a second oil opening (414, 415) are provided so as to be connected to the internal cavity of the oil cylinder, the first oil opening is connected by a hydraulic pipe to the master cylinder (2, 20), the second oil opening is connected by a hydraulic pipe to the working cylinder (3, 30), and, of the first and the second oil opening (414, 415), at least one oil opening is situated on the cylinder wall of the oil cylinder; a first piston which is situated movably in the internal cavity, wherein the first piston is in sealing contact with the cylinder wall, and the first and the second oil openings (414, 415) have a spacing in a movement direction of the first piston; a drive apparatus for driving the first piston for movement in the internal cavity; a control unit (5b, 441) which is used to the effect that: upon receipt of commands from the automatic controller, the drive apparatus (5, 40) is controlled so as to automatically drive the first piston in accordance with the preset program, such that said first piston moves in a position range which has the effect that the first and the second oil opening (414, 415) are not connected, characterized in that, upon receipt of commands from the controller by a person, the control unit (5b, 441) controls the drive device so as to drive the first piston in such a way that the latter immovably maintains a position which generates a connection of the first and of the second oil opening (414, 415). an oil cylinder, wherein, on the oil cylinder, a first and a second oil opening (414, 415) are provided so as to be connected to the internal cavity of the oil cylinder, the first oil opening is connected by a hydraulic pipe to the master cylinder (2, 20), the second oil opening is connected by a hydraulic pipe to the working cylinder (3, 30), and, of the first and the second oil opening (414, 415), at least one oil opening is situated on the cylinder wall of the oil cylinder; a first piston which is situated movably in the internal cavity, wherein the first piston is in sealing contact with the cylinder wall, and the first and the second oil openings (414, 415) have a spacing in a movement direction of the first piston; a drive apparatus for driving the first piston for movement in the internal cavity; a control unit (5b, 441) which is used to the effect that: upon receipt of commands from the automatic controller, the drive apparatus (5, 40) is controlled so as to automatically drive the first piston in accordance with the preset program, such that said first piston moves in a position range which has the effect that the first and the second oil opening (414, 415) are not connected, characterized in that, upon receipt of commands from the controller by a person, the control unit (5b, 441) controls the drive device so as to drive the first piston in such a way that the latter immovably maintains a position which generates a connection of the first and of the second oil opening (414, 415). upon receipt of commands from the automatic controller, the drive apparatus (5, 40) is controlled so as to automatically drive the first piston in accordance with the preset program, such that said first piston moves in a position range which has the effect that the first and the second oil opening (414, 415) are not connected, characterized in that, upon receipt of commands from the controller by a person, the control unit (5b, 441) controls the drive device so as to drive the first piston in such a way that the latter immovably maintains a position which generates a connection of the first and of the second oil opening (414, 415).