A shock absorber includes a first and a second passage configured to flow a working fluid out of one chamber by movement of a piston, a first damping force generation mechanism installed at the first passage and configured to generate a damping force, a housing having at least a partial passage of the second passage formed therein, a free piston movably installed in the housing and configured to partition the second passage into an upstream side and a downstream side, and a spring member disposed in the housing and configured to hole the free piston at a neutral position, wherein a second damping force generation mechanism including a friction member installed at an inner side of the cylinder with respect to the sealing member and constituted by an annular elastic rubber section in sliding contact with the piston rod and an annular base section to which the elastic rubber section is fixed and a communication passage configured to reduce a pressure difference between both sides in an axial direction of the friction member is provided.