A damper (D1) comprising an actuator A connected to a sprung member (B) side of a vehicle, the actuator having a motion converting mechanism (T) for converting a linear motion into a rotational motion and a motor (M) to which the rotational motion resulting from the conversion by the motion converting mechanism (T) is transmitted; a hydraulic damper (E), the hydraulic damper (E) having a cylinder (C), a piston (P) inserted slidably into the cylinder (C) and defining two pressure chambers within the cylinder (C), and a rod (R) connected at one end thereof to the piston (P), the linear motion of the actuator (A) being transmitted to one of the rod (R) and the cylinder (C), the other of the rod (R) and the cylinder (C) being connected to an unsprung member (W) side of the vehicle; a spring (1) accommodated within one of the two pressure chambers and biasing the hydraulic damper (E) in a damper compressing direction; and a spring (2) accommodated within the other pressure chamber and biasing the hydraulic damper (E) in a damper extending direction.