To prevent discharge of grain with waste straw by removing free grain from threshed waste straw.

The thresher is provided with a feed chain (5a) on a threshing port (7d) formed on the outside of the threshing chamber (6) for conveying threshed grain culms, a threshing cylinder (7a) provided with many threshing cogs (7b) on the inside of the threshing chamber (6), and a threshing net (7c) on the lower periphery of a rotation trajectory of the threshing cogs (7b) provided on the threshing cylinder (7a). The rear end of threshing cylinder (7a) is set so as to project backward from the rear end of the threshing net (7c), pivoting the rear end side of the threshing shaft (7) supporting the threshing cylinder (7a) on the threshing chamber rear plate (6b), a free grain recovering part (B) is formed between the threshing chamber rear plate (6b) and the threshing chamber middle rear plate (6d) disposed on the front side of the threshing chamber rear plate (6b) with an interval, and a guide (48c) which supports grain culms conveyed by the feed chain (5a), is set to project backward from the threshing chamber middle rear plate (6d) side, on the lower part of the free grain recovering part (B).