Abstract: Both ends of a bellows-type outer cylinder [31] capable of axial expansion and contraction are connected in a leakproof manner to a pair of connection passage ends [20], thereby constituting an expansion passage [30]. A cylindrical resin film [33] having no permeability to fluid is arranged in an interior of the bellows-type outer cylinder [31], and the axial ends thereof are connected in a leakproof manner to said connecting passage end regions. The cylindrical region [34] positioned in the intermediate region of the cylindrical resin film [33] covers the inner surface of said bellows-type outer cylinder [31] in a leakproof manner.