To prevent positional dislocation of an assembled part obstructing smooth assembly from generating at assembling a hydraulic shock absorber.

On the way of a piston rod extending outward from a shock absorber main body, a flange part 3t gradually spreading the diameter toward the shock absorber main body 2 side, and after reaching the maximum diameter, returning to the original diameter through a step part is formed, the piston rod 3 is partitioned into an invasion part 3a and a mount part 3m defining the flange part 3t to be the boundary, and a stopper rubber 10 is fitted to the position contacted with the flange part 3t in the invasion part 3s. In this case, the invasion part 3s and the mount part 3m are separated members from each other, and the flange part 3t can be formed on either end part of the invasion part 3s or the mount part 3m.