PURPOSE: To optimize control of a shock absorber by adjusting the damping characteristics of the shock absorber during operating phases of slight damping force changes. CONSTITUTION: Signals detected from the movement of a vehicle are inputted into a means 19 which operates based on a sky hook adjustment constitution, and the signals are introduced into a shock absorber 18 through a signal path 11 and a traction stage commands Zw/Zn. Signals of a spring deflection sensor or an absorber press sensor are inputted into a second device 15 with a signal from a means 20 and the signals K1 and K2 which has a prescribed value, represents a driving state or affects, via a first device 14 having differential characteristics as a spring deflection velocity Xar' (t), by the means 20 to operate a switch 13. Accordingly, the damping characteristic is adjusted during the operating phases of slight damping force changes, and a changeover noise and adjusting effects can be improved.