PURPOSE: To use up whole wire coil and to exchange wire coil without interrupting the operation on user side in a continuous wire supplying method by which the wire is continuously supplied while the wire coils are successively exchanged.

CONSTITUTION: A first coil 11 is spirally wound with a wire 12 whose both ends 12a and 12b are left outside and used while unwound from one end 12b. A second wire coil 21 is spirally wound with a wire 22. Another end 12a of the wire 12 is welded to one end 22b of the wire 22 before the whole wire 12 is used up. The welded part is cold-worked and the second wire coil 21 is used while unwound from 22b from one end of the wire 22, successively after the wire 12 is used up.