DAMPER

PURPOSE: To prevent the transmission of vibration and the outflow of electric viscous fluid while adjusting a damping force in a wide range in a damper using the electric viscous fluid. CONSTITUTION: Piston bodies are disposed at a predetermined interval in a cylinder 12 storing electric viscous fluid. A piston part 14 has a bulging part 14D formed at both ends into the round shape and the lower end formed into the round shape having the large radius of curvature and smoothly contiguous to the bulging part 14D. Since the resistance of the piston body in the move time is lessened, a damping force when voltage is not applied to the electric viscous fluid 24 can be restrained low and a difference between the sizes of the damping force can be enlarged, i.e., a range of adjustment of the damping force can be widened. Also, since the piston rod 14C is formed thinner than the piston body, a change in the liquid level in the moving the piston body can be reduced.