A twin-tube shock damper has a hollow piston rod (5) which extends towards the top of the working cylinder (1), a baseplate (8) which closes off the working cylinder and a disc (7) which is arranged inside the working cylinder between the piston (4) and the baseplate and has one or more passages (16) and a non-return valve (17) which allows upward flow through the passages, a central tube (10), a connection (11) between the hollow piston rod and the space above the piston, a damping valve (21) which operates in one direction of flow and servo-control means having an excitation chamber (18) and an excitable coil (30). A control valve in the form of a hollow piston (25) movable in a control valve cylinder (22) provided with orifices (24) and a hollow shaft (27) guided in a valve shaft guide (26) provided with orifices (28) are located in the excitation chamber. Both the control valve cylinder and the control valve are pushed by spring means (23, 29) in the direction of the damping valve body (17).