PROBLEM TO BE SOLVED: To embody damping action of an extension side and a pressure side using a built-in damper by operation of a single actuator, as well as improving comfort in a two-wheeler.SOLUTION: The damper included in a fork body having an inner reservoir R and embodying the damping action, has a control means (8) for allowing working fluid to flow out to the reservoir R via the inside of a rod body 4 and an upper-end opening of the rod body 4 from the inside of a cylinder body 3 in expansion operation for moving the rod body 4 into/from the cylinder body 3, facing the upper end opening of the rod body 4 and applying flow passage resistance to the working fluid of flowing out of the upper end opening of the rod body 4. This control means (8) is connected to a driving means (7) arranged in an upper end part in a vehicle body side tube 1, and the extension side and pressure side damping action in the damper is embodied by driving of the driving means (7).