To provide a method for manufacturing wire rods capable of preventing fluctuations of free coil diameters.

A device for manufacturing wire rods 1 comprises a drawing die 3, a first optical sensor 5, a shaving die 7, a second optical sensor 9, an outside casting roller 11, an inside casting roller 13 and a winding cylinder 15. A wire stock material 17 is bent by the inside casting roller 13. A diameter of the wire stock material 17 before the shaving process is measured by the first optical sensor 5 and the diameter of the wire stock material 17 after the shaving process is measured by the second optical sensor 9, from both of which a reduction is calculated. The inside casting roller 13 travels in accordance with the diameter of the wire stock material 17 after the shaving process and the reduction. By this way, the bending degree of the wire stock material 17 is changed.