PURPOSE: To enhance the strength and flexibility of the resulting thin Cu clloy wire and to reduce the manufacturing cost by using a Cu alloy having a specified composition contg. Sn and Mn.

CONSTITUTION: A rough wire of an alloy consisting of 0.1W2.0% Sn, 0.1W0.5% Mn and the balance Cu or a wire rod obtd. by drawing the rough wire is annealed, pickled, and scalped. This wire rod 1 is supplied from a supplier 2 and drawn by passing through drawers 3, 4, 5 in succession, and it is further drawn by passing through a reverse tension drawer 6. Thus, the rod 1 is drawn to ≤ about 1.0mm prescribed diameter at ≥99.5% reduction ratio. The resulting wire is passed through a roll leveler 7 to provide high flexibility with ≤0.9 ratio between 0.2% yield strength and tensile strength without reducing the strength excessively, and it is coiled around a coiler 8. This thin Cu alloy wire is suitable for the winding of various electric apparatus and the heating wire of an electric blanket.