A damping valve includes a piston, a damping passage, a piston rod, a bypass, and a relief valve, and the bypass includes a valve hole extending in the axial direction of the piston rod and a horizontal hole opening from a side part of the piston rod and leading to the valve hole, and the relief valve includes an annular valve seat provided on the side of a pressure side chamber with respect to an opening of the horizontal hole, a valve body slidably inserted on the side of an extension side chamber with respect to the annular valve seat and partitioning a back pressure chamber in the valve hole, a bias spring biasing the valve body toward the annular valve seat, and a throttle communicating the back pressure chamber with the extension side chamber.