A combine harvester is provided with: a threshing device that performs a threshing process of threshing a crop; a grain tank that stores grain obtained by the threshing process; a grain discharging device that discharges grain to be stored in the grain tank to the outside of the vehicle body; a travel driving device that drives travel of the vehicle body; and an engine that serves as a power source. The combine harvester includes a first relay shaft to which power is transmitted from an output shaft of the engine, and the power of the engine is transmitted from the first relay shaft to the grain discharging device and the travel driving device in a branched manner.