To provide a pneumatic buffer capable of improving a vehicle riding comfort.

The pneumatic buffer A comprises a cylinder 1, a piston 3 sectioning the interior of the cylinder 1 into a rod side chamber R1 and a piston side chamber R2, and a rod 4 movably inserted into the cylinder 1 through the piston 3. Because the pneumatic buffer A includes a volume change absorption mechanism 30 for absorbing the volume change of working gas, a pressure fluctuation in the cylinder 1 caused by the volume change of the working gas is prevented by the volume change absorption mechanism 30 to thereby reduce the change of posture of the vehicle and improve the vehicle riding comfort.