To lower a strength of an adjustable damping force damper while securing maneuvering stability and comfort of a vehicle.

As adjustable damping force of the adjustable damping force damper has its maximum valve within a low piston speed area in which the piston speed is not less than 0.1 m/s and less than 0.3 m/s, the maneuvering stability is secured by enhancing the total damping force of basic damping force and the adjustable damping force in the low piston speed area and suppressing change in a rolling attitude and change in a pitch attitude of the vehicle. Not only securing the comfort of the vehicle but also preventing excessive load from being applied on the damper are provided by preventing the total damping force from being excessive in a high piston speed area, which lowers the strength of the damper to perform simplification of the structure, reduction in weight, downsizing, and cost reduction.