A shock absorber includes: a damping valve that suppresses a flow of operating fluid due to the sliding of a piston to generate damping force; a bottomed tubular pilot case that forms a pilot chamber that causes pressure to act on the damping valve in a valve closing direction, together with the damping valve; and an annular seal member (146) that is provided to be fixed to the outer circumferential side of a rear surface of the damping valve, and is fitted into a tube of the pilot case so as to be slidable and to be in a liquid tight manner. A part of the flow of the operating fluid is guided to the pilot chamber and opening of the damping valve is suppressed by the pressure of the pilot chamber. An annular concave portion (380) is formed on the outer circumferential side of the seal member (146), and an annular convex portion (385) is formed on the inner circumferential side of the seal member (146).

A shock absorber includes: a damping valve that suppresses a flow of operating fluid due to the sliding of a piston to generate damping force; a bottomed tubular pilot case that forms a pilot chamber that causes pressure to act on the damping valve in a valve closing direction, together with the damping valve; and an annular seal member (146) that is provided to be fixed to the outer circumferential side of a rear surface of the damping valve, and is fitted into a tube of the pilot case so as to be slidable and to be in a liquid tight manner. A part of the flow of the operating fluid is guided to the pilot chamber and opening of the damping valve is suppressed by the pressure of the pilot chamber. An annular concave portion (380) is formed on the outer circumferential side of the seal member (146), and an annular convex portion (385) is formed on the inner circumferential side of the seal member (146).