To realize a compact device which performs a volume change in a quick response and sufficiently withstands pressure wave motions exceeding 200 MPa.

In a diameter of a rubbery outer shell of a granular body is 12 mm or less and its thickness is from one tenth of the diameter to 2 mm, and hollow ball-shaped balloons or capsule-shaped small disk bodies made of fluoride rubber being rich in an oilproofness and durability are formed in the pressure wave motion damping device. A granular elastic pressure receiving body 21 having elasticity which generates no buckling by withstanding high pressure is prepared for the pressure wave motion damping device while inactive gas is filled up under a suitable initial pressure, the elastic pressure receiving granular body 21 is disposed on a section connected with a single or a plurality of fluid passages, wave motions of the fluid pressure is absorbed by changing a volume of the elastic pressure receiving granular body 21 having an elasticity in response to the fluid pressure applied on the pipe, and then, the pressure wave motions are damped in the pressure wave motion damping device.