PURPOSE: To easily obtain the displacement amount which is given to the pulsation pressure generating means with a simple and inexpensive structure, and absorb pulsation pressure efficiently by measuring directly the amount of non- steady flow discharged from a pulsation pressure source, and generating fluid pulsation pressure so as to negate a volume change by a flow rate change.

CONSTITUTION: A pulsation pressure source 1 on one end and a load on the other end are connected to each other by a fluid pressure circuit 2. A pulsation generating means 4 which generates fluid pulsation pressure by applying voltage to a piezoelectric element 3 is disposed in the mid of the fluid pressure circuit 2. At this time, a non-steady flow amount measuring means 7 which measures the amount of non-steady flow fluid discharged from the pulsation pressure source 1 is disposed at the fluid circuit 2 on the pulsation pressure source 1 side near the pulsation pressure generating means 4. Besides, voltage applied to the piezoelectric element 3 is controlled by a pulsation pressure absorption control means 8 so as to negate the measured flow rate change. It is thus possible to obtain displacement amount easily for effective absorption of pulsation pressure without adding a sensor and its control as well as adjustment by a change in the fluid pressure circuit.