A shock absorber includes a cylinder, a piston, a piston rod, a damping passage, a bypass path, a shutter, a biasing member, and a control spring secured to the cylinder by one end. Another end of the control spring is opposed to the shutter. When the piston exceeds a predetermined position with respect to the cylinder by displacing on the compression-side chamber side, the shutter is pushed by the control spring and closes the bypass path. The control spring is a conical coil spring. The other end side of the control spring has a small diameter. A guide ring, which is slidably in contact with an inner periphery of the cylinder, is mounted to the small-diameter side end of the control spring.