SHOCK ABSORBER AND METHOD FOR MANUFACTURING SHOCK ABSORBER

Provided is a shock absorber in which trivalent chromium is used to achieve both high hardness and low frictional force at a high level without using hexavalent chromium which is suspected of causing damage to the human body and the environment, and a method for manufacturing the shock absorber. A shock absorber () of the present invention includes: a cylinder () which is filled with hydraulic oil (); a piston rod () which is movable in the cylinder (); and an oil seal () which is fixed to the cylinder () and slides on the piston rod (), in which a hard layer mainly containing chromium obtained from a trivalent chromium plating bath is provided on a surface of the piston rod (), and the hard layer contains both a crystalline material and an amorphous material, and also contains an additive other than chromium.