A harvester capable of autonomous travel in a field includes: a harvesting unit that harvests a crop from the field； a conveyance device 12 that conveys, toward the rear of a harvester body, a whole culm of the harvested crop harvested by the harvesting unit； a detection sensor 37 that detects a drive speed of the conveyance device 12； and a clog determining unit 73 that determines a clog of the harvested crop in the conveyance device 12 on the basis of the drive speed. The clog determining unit 73 outputs a vehicle stop command that stops the harvester body when the drive speed becomes lower than a pre-set first threshold during the autonomous travel.
