A threshing device capable of solving a problem wherein sorting treatment cannot be sufficiently performed when grains and waste straw flowing down from a threshing part are carried to a chaff sieve in large quantities at a time or the grains are wet. In the threshing device having a threshing part (20) and a sorting part (30), a sieving device (120) is installed between a receiving net (23) and asuction fan (40) disposed at the rear of the receiving net on its extension on the lower side of the threshing cylinder (22) of the threshing part (20) and on the upper side of the swing sorting device (31) of the sorting part (30). A guide member (121) is installed between the receiving net (23) and the sieving device (120).