To facilitate carriage and stacking and to prevent generation of surplus products by cutting the skelp before the leveling process after the uncoiling process, and storing the remaining coil in a condition where a tip of the coil is wound.

A skelp 5 between a coiler 2 and a lever 21 is cut by a plasma cutting device provided below the skelp, and the remaining coil is stored with its tip wound therearound to facilitate the carriage and stacking, and to prevent generation of surplus products. A plasma torch 11 is installed at the angle of inclination of ≥45° and <90° of the skelp 5 relative to a plate on the downstream side of the advancing direction of the skelp 5. This is installed so that more molten slag is adhered to a cut side on the coil side by the plasma flow, and the slag is cut at a crop shear on a lever outlet side during the use, and no roll flaw is generated.