PROBLEM TO BE SOLVED: To improve purification efficiency of exhaust gas of an engine by effectively using a space around a grain tank to set an exhaust gas purifier.SOLUTION: A starting end part of a DOC (diesel oxidation catalyst) part (16) is connected to an exhaust manifold (13) of an engine (11), a starting end part of SCR (selective catalytic reduction) (17) is connected to a terminal end side of the DOC (16) part, and the DOC part (16) and the SCR (17) are arranged below an inclined surface (21) formed in the inside lower part of a grain tank (5). The terminal end side of the DOC part (16) and the starting end part of the SCR (17) are connected to each other through an intermediate connection exhaust pipe (14B), a lateral part of the intermediate connection exhaust pipe (14B) between the DOC part (16) and the SCR (17) is formed with a recessed space (26), and a grain lifter (27) which feeds grains from a thresher (3) to the grain tank (5) is made to enter into the recess space (26).【課題】グレンタンク周辺のスペースを有効利用して排気浄化装置を配置し、エンジンの排気の浄化効率を向上させる。【解決手段】エンジン（１１）の排気マニホールド（１３）にＤＯＣ（１６）部の始端部を接続し、ＤＯＣ（１６）部の終端側にはＳＣＲ（１７）の始端部を接続し、ＤＯＣ（１６）部とＳＣＲ（１７）をグレンタンク（５）の内側下部に形成される傾斜面（２１）の下方に配置する。また、ＤＯＣ（１６）部の終端側とＳＣＲ（１７）の始端部を、中間接続排気管（１４Ｂ）を介して接続し、ＤＯＣ（１６）部とＳＣＲ（１７）の間における中間接続排気管（１４Ｂ）の側方の部位に凹部空間（２６）を形成し、脱穀装置（３）からグレンタンク（５）に穀粒を投入する揚穀装置（２７）を凹部空間（２６）に入り込ませる。【選択図】図４
