To provide a piston for a damper, which uses the same passage for bidirectional flowing of fluid, and comprises a float valve.

A piston with a valve for a hydraulic damper tube has a piston body 116 which has a fluid passage, and the passage interacts with a floating valve element which bidirectionally controls the flow of the fluid flowing in this passage. The floating valve element has a spring washer 115, and the amount of deviation f of the spring washer 115 in a free state is approximately 0.1 to 2 times as large as the thickness e of the washer.