Abstract: In the process of boning a poultry leg (including a thigh bone and tibia) or separating the bones from the meat using a belt-shaped cutter, the poultry leg is held in such a manner that the thigh bone and tibia form a predetermined angle between them. The belt-shaped cutter is wounded on the bone, and slides along the extending direction of the thigh bone and tibia while the opposite ends of the belt are moved reciprocally alternately, whereby the bone is separated from the meat. At the pre-processing stage, the poultry leg has been severed by means of a cutting device such as knife, etc. along the extending direction of the bone at the opposite side thereof to that on which the belt-shaped cutter is wound, so that the meat thus cut depends down from the severing line owing to its own weight. Therefore, the meat portion not yet thus severed and surrounding the bone is separated by means of the belt-shaped cutter.