An object of the invention is to achieve compatibility between a cost reduction on the basis of a structure simplification and an improvement of a threshing efficiency. A conventional combine harvester of the invention is provided with a reaping device 3 having a reaping blade 15, and a threshing device 9 having a threshing cylinder 21, and is structured such as to supply reaped grain culms from the reaping device 3 to the threshing device 9 via a feeder house 11. The threshing cylinder 21 has a plurality of bone frames 145 extending in parallel to a threshing cylinder shaft 20, being arranged in a peripheral direction of the threshing cylinder 21 and having a polygonal cross-sectional shape, and a lot of rod shaped threshing teeth 146 which are provided in the bone fi-ame 145 so as to protrude outward. Each of the bone frames 145 is supported to the threshing cylinder shaft 20 via a support body 140.
