Abstract: An object of the invention is to provide a shock absorber which can reduce damage to the member to collide therewith. The invention provides a shock absorber comprising a cushion structure of three-dimensional spring construction, which has a large void provided by a random curl or loop formed by hot extruding a thermoplastic resin to form a continuous strip and curling or looping the strip in a molten state to bring adjoining strip sections into interlocking contact with each other. In the invention, the cushion structure may be obtained by stacking a plurality of cushion structure members, each having high cushion performance and buckling resistance and a certain thickness, one upon another parallel in a thickness direction or rolling up one side of a cushion member with a given thickness. Then, the cushion structure is embedded in a foamed and hardened filler containing a hydratable, hydraulic binder while a part of the cushion structure is exposed on an shock-receiving surface.