<p>This controller (M3) controls a variable damping force shock absorber (M2) taking the cycle time and the oscillating phase of the body vibration. The controller increases the damping force when the body is moving toward its mean position. Before that, the damping force is kept weak so that the body vibration is hastened to become moving toward the mean position. Some criteria for determining that the body is moving toward its mean position are proposed. </p>