Abstract: The present invention provides a damping force variator that can damp a vibration even if the frequency of the vibration is high. The damping force variator, which applies a magnetic field to a magnetic fluid flowing through an orifice to vary the magnitude of a damping force, has a float that moves in the orifice when the magnetic fluid flows. If the damping force variator has a cylinder that is filled with the magnetic fluid, and a piston that slides in the cylinder to apply a pressure to the magnetic fluid, the damping force variator functions as a damper that damps a vibration transmitted from the cylinder or the piston.