A shock absorber includes a first damping force generation mechanism provided in a first passage, and a second damping force generation mechanism provided in a second passage, in which the second damping force generation mechanism includes a first valve seat formed on a case member having a cylindrical part and a bottom part, a disc valve in which a separable part on an outer circumferential side is separably disposed on a first valve seat, and a second valve seat provided on a side of the disc valve opposite to the first valve seat and configured to support the disc valve on a radial inner side of the separable part, and the second passage includes a piston rod passage part formed by cutting out or penetrating the piston rod, and a chamber passage part which allows communication from the piston rod passage part to a case inner chamber.