To provide a tension device capable of controlling the tension of a thin wire rod in a careful manner.

When an air pressure source 150 feeds air into an air chamber 133e through a hose H and a connector C, the air is supplied to a through hole 141 of a cylindrical hollow member 140 only through opening upper inclined holes 142 since lower inclined holes 143 are closed by an inner surface of a stage 133x, which provides an upward gas flow in the through hole 141 (as shown in Fig.2). Thereafter, releasing the wire rod W by a cutting and holding mechanism and rotating a rotation shaft 122 causes the wire rod W to be wound around an outer circumferential surface of a bobbin B. On this occasion, the wire rod W passing through the through hole 141 receives a resistance by the upward air flow, with a desired tension applied thereto.