PROBLEM TO BE SOLVED: To provide a combine harvester having a cleaning device excellent in durability and a grain tank capable of storing a large quantity of grains.SOLUTION: In the combine harvester, a DPF unit (40) for cleaning the exhaust gas of an engine (9) is arranged at a site on the machine frame lateral center side which is the lateral side of a thresher (5), and the gas-exhausting manifold (30B) of the engine (9) is connected to the air intake opening (40E) of the DPF unit (40) through flexible connection pipes (52, 72, 92). The DPF unit (40) is disposed between the thresher (5) and a grain tank (6), an inclined wall (21D) downward inclined toward outside the machine frame is provided at the lower part of the grain tank (6), and inserting the DPF unit (40) into a space under the inclined wall (21D).
