The invention provides a combine harvester, and the combine harvester enables a reverse rotation mechanism to be small, and improves the maintenance of the reverse rotation mechanism. The combine harvester is provided with a transmission path for driving a harvesting device (4) and a conveying lifter (14) through a rotating drive force of an engine (21); a reverse rotation mechanism (20). The reverse rotation mechanism (20) is configured at a harvesting support part (27), and resversely drives the harvesting device (4) and the conveying lifter (14). The reverse rotation mechanism (20) is provided with a first straight gear (26) which is used for inputting the rotating drive force from the transmission path; and a second straight gear (25) which is engaged with the first straight gear (26) and enables the reverse rotating drive force to the harvesting device (4) and the conveying lifter (14).