PROBLEM TO BE SOLVED: To improve the handling of grain culms by reducing the diameter of the terminal end of the handling cylinder and lengthening the handling teeth of the small diameter handling cylinder to be substantially the same as the rotation trajectory of the tips of the handling teeth of the large diameter handling cylinder. To reduce the mixing of tea grains and to significantly reduce losses and at the same time reduce the threshing load. According to the present invention, in a combine threshing device (4) for threshing a grain culm supplied into a handling chamber (9) by rotation of a handling barrel (10), a terminal side of the handling barrel (10). Is formed to have a diameter smaller than the diameter of the starting end side, and the rotation locus of the tips of the treating teeth (11b) of the small diameter side treating cylinder (10b) formed on the terminal side of the treating cylinder (10) is changed to the handling cylinder (10). (3) is a threshing device for combine harvesters, which is set to have substantially the same diameter as the rotation locus of the tips of the handling teeth (11a) of the large diameter handling cylinder (10a) formed on the starting end side. [Selection diagram] Fig. 3【課題】扱胴の終端側を小径化し、その小径扱胴の扱歯は長くして大径側扱胴の扱歯先端の回転軌跡と略同一にすることで、穀稈のさばきを良くしてささり粒の混入を減少し、ロスの大幅解消と同時に脱穀負荷の軽減を図ること。【解決手段】本発明は、扱室（９）内に供給された穀稈を扱胴（１０）の回転によって脱粒処理するコンバインの脱穀装置（４）において、前記扱胴（１０）の終端側の直径を始端側の直径よりも小径に形成し、この扱胴（１０）の終端側に形成された小径側扱胴（１０ｂ）の扱歯（１１ｂ）先端の回転軌跡を、扱胴（１０）の始端側に形成される大径側扱胴（１０ａ）の扱歯（１１ａ）先端の回転軌跡と略同径に設定してあることを特徴とするコンバインの脱穀装置である。【選択図】図３
