Abstract: A hydraulic buffer includes a cylinder, a piston disposed movably in the cylinder to partition the interior of the cylinder into two liquid chambers, and a piston rod connected to the piston and having a first path communicating with one of the liquid chambers and extending axially beyond the piston and a second path communicating with the other of the liquid chambers. A solenoid valve received in the piston rod has a tubular spool disposed movably axially of the piston rod and has a third path capable of communicating with the second path in the piston rod. Further, inside the spool is disposed a pipe having a fourth path capable of communicating with the third path in the spool and communicating with the first path in the piston rod.