PROBLEM TO BE SOLVED: To solve a problem in a conventional threshing cylinder that a drum part is formed by blocking a portion between cross piece members adjacent in a rotation direction with a shield member and deformation occurs due to lack of support in a radial direction of the drum part when a load within a threshing chamber is increased.SOLUTION: In a threshing cylinder 21, threshing tooth support members 25 arranged with plural threshing teeth 20 are arranged at a predetermined interval to a threshing cylinder shaft 26 in a radial direction, threshing tooth support members 25 are arranged at a predetermined interval to each other in a circumferential direction, a drum part 27 having a polygonal cross section is arranged inside the threshing tooth support members 25, the drum part 27 and threshing tooth support members 25 are arranged such that an apex 30 of the drum part 27 faces a portion between the threshing tooth support members 25 in a circumferential direction of the threshing cylinder shaft 26, and a shield plate 45 extended from an outer peripheral face of the drum part 27 toward the threshing tooth support member 25 blocks a portion between the drum part 27 and threshing tooth support member 25. The threshing device is thus configured.SELECTED DRAWING: Figure 4
