To provide a damper capable of improving riding comfort in a vehicle by exerting optimal damping force with excellent responsiveness.

The damper includes a cylinder 1, a piston 2 slidably inserted in the cylinder 1 and partitioning the inside of the cylinder 1 into two pressure chambers R1, R2, and a rod 3 slidably inserted in the cylinder 1 and connected with the piston 2. In expanding and contracting, the damper performs a predetermined damping effect while working fluid is made to flow into and out of the cylinder 1 via a pipe L making one pressure chamber R2 communicate with a cylinder external device 10. The damper comprises a hollow joint 5 connecting the pipe L with a sealing member 4 for sealing one end of the cylinder 1, and making the inside of the pipe L communicate with one pressure chamber R2, a check valve 6 in the joint 5 allowing only flow of working fluid from the pipe into one pressure chamber R2, and a valve element 7 applying resistance to the flow of working fluid from one pressure chamber R2 into the pipe L.