PURPOSE: To freely perform the change of thickness and surface finish of a material by providing a tension controller between a drawing process and an annealing process, by which the rotation speed of a tension separating motor is controlled in accordance with the quantity of deformation inputted of a deformation gauge.

CONSTITUTION: In a tension adjusting machine arranged in the passage of an extra fine wire between a drawing process and an annealing process, the minute displacement force of a dancer roll 13 is enlarged by a lever 27 supported at a fulcrum 26 and transmitted to a tension spring 28. The displacement force so transmitted to the tension spring 28 is further transmitted from the spring to an elastic body bar 30 and, by detecting it by a deformation gauge 31 in terms of deformation quantity, the minute displacement force is detected. A tension separation spool which is arranged on the side of the drawing process from the dancer roll 13 is controlled by a tension controller 25 in accordance with the deformation quantity detected by the deformation gauge, and the variation is thereby controlled of the minute tension at the annealing process. Consequently, the generation of scrap quantity is little, and there is no half-finished state of an intermediate stock.