To easily remove a packing cloth from a raw fiber sack by simple work without requiring a specific labor power for handling and without damaging working environment caused by scattering of the raw material, though the handling to remove the packing cloth, especially the lower one has been difficult caused by the heavy weight of the raw material sack weighing 250-300 kg.

This method for removing a packing cloth from a raw fiber sack is to lay the raw fiber sack on a sack-opening conveyor, cut a metal fixture of the raw fiber sack and, at the same time, remove an upper packing cloth DA, successively open a lower packing cloth DB, fix a suitable portion of the opened end of the lower packing cloth, successively turn a sack-opening conveyor synchronously with an adjacent accepting conveyor C to turn the lower packing cloth DB with the sack-opening conveyer and transfer the raw fiber solely laid on the conveyor toward the conveyor C.