There is provided a damper that can reduce a shock when a piston speed reaches a high speed range from a low speed range without deteriorating a ride comfort while the piston speed is in the low speed range. In order to solve the above-mentioned problem, in a damper D of the present invention, since a orifice (7) and an opening/closing valve (9) are arranged in parallel with a bypass passage (B) bypassing a damping passage (3), and a valve opening pressure of an opening/closing valve (9) is made lower than a valve opening pressure of a damping valve (5), a sudden change in an inclination of a damping force characteristic can be moderated at an inflection point of the damping force characteristic even if the damping force is increased while the piston speed is in the low speed range.