Suspension apparatus and suspension system

A first front fork includes an outer tube, an inner tube, a tubular cylinder provided inside the outer tube and the inner tube, a rod member moving relatively in an axial direction of the cylinder and having a space portion inside, which is formed in the axial direction, a piston fixed to an end portion of a wheel side of the rod member and sectioning a space in the cylinder into part of a rebound air spring chamber and an inner air spring chamber and a rod guide fixed to an end portion of a vehicle-body side of the cylinder and sectioning a space in the inner tube into part of the rebound air spring chamber and an outer air spring chamber.