To provide a long material feeding method and its device in a cutting machine capable of shortening the tact time and improving the positioning accuracy.

A fore-vice 21 is positioned closest to a cutting machine 3 by a control device 9, a long material is carried to a position at which the fore-vice 21 can clamp the long material W, by a material carrying vice 15, and the long material is grasped by the fore-vice 21 to unclamp the material carrying vice 15. The position of the material carrying vice 15 at this time is detected by a material carrying vice position detecting means 17. The long material is carried by the fore-vice 21 to be positioned in the neighborhood of a desired length. The length of the material carried at this time is detected by a fore-vice position detecting means provided at the fore-vice 21. Then the long material is clamped by the material carrying vice 15, and final positioning of the long material is performed by moving the long material by means of the material carrying vice 15 while the long material is detected by the fore-vice position detecting means.