To provide a combine harvester which can efficiently separate and filter foreign matters such as waste straw in second crops in a grain-lifting cylinder for returning second crops to a thresher.SOLUTION: A first grain-lifting cylinder (36) for conveying grains from a thresher (4) to a grain tank (7) is provided, and a second grain-lifting cylinder (41) for returning second crops from the lower part to the upper part of the thresher (4) by connecting the rear part and the front part of a right wall (4B) of the thresher (4) is provided in a rear lower inclined posture at the left side of the first grain-lifting cylinder (36). A conveying spiral (46) and a cylindrical body (45) covering the conveying spiral (46) are provided in the second grain-lifting cylinder (41), and a discharged dust filtering member (42A) having a plurality of filter holes is provided in a dust discharging port (42) formed at the lower surface side of the second grain-lifting cylinder (41). The inner peripheral surface of the discharged dust filtering member (42A) is arranged closer to the outer peripheral edge of the conveying spiral (46) than the inner peripheral surface of the cylindrical body (45).SELECTED DRAWING: Figure 13【課題】脱穀装置に２番物を還元する揚穀筒において、２番物中の藁屑等の來雑物を効率的に分離、濾過することができるコンバインを提供する。【解決手段】脱穀装置（４）からグレンタンク（７）へ穀粒を搬送する第１揚穀筒（３６）を設け、第１揚穀筒（３６）の左側に、脱穀装置（４）の右壁（４Ｂ）の後部と前部を連結して脱穀装置（４）の下部から上部へ２番物を還元する第２揚穀筒（４１）を後下がり傾斜した姿勢で設け、第２揚穀筒（４１）に、搬送螺旋（４６）と、この搬送螺旋（４６）を覆う筒体（４５）を設け、第２揚穀筒（４１）の下面側に形成される排塵口（４２）に、複数の濾過孔を有する排塵濾過部材（４２Ａ）を設け、排塵濾過部材（４２Ａ）の内周面を筒体（４５）の内周面よりも搬送螺旋（４６）の外周縁に接近させて配置した。【選択図】図１３
