A combine harvester includes: a grain conveyance mechanism for conveying grains from a threshing apparatus to a grain tank; a grain discharge apparatus provided in an end area of the grain conveyance mechanism, the grain discharge apparatus having a discharge case provided with a grain discharge opening, and a discharge rotor rotatably arranged in the discharge case; a pressed portion that is subjected to a pressing force applied by grains immediately before the grains are discharged by the discharge rotor; a load detector for detecting the pressing force exerted on the pressed portion; and a yield evaluator for evaluating the amount of conveyed grain based on a detection signal from the load detector.