PROBLEM TO BE SOLVED: To provide a combine harvester for accurately detecting the amount of grain stored at a storage part by using an appropriate coefficient corresponding to a mounting position and a mount posture of a pressure detection means and a type to be harvested for a function indicating a relationship between a detection result of the pressure detection means and the amount of grain.SOLUTION: An unknown coefficient is obtained based on a detection result of a charging port sensor 23a and the amount of grain obtained by calculation, a real function is derived, and an appropriate real function corresponding to various conditions, such as a difference in the mounting position and mount posture of the charging port sensor 23a to a grain tank 4, and a type to be harvested is used to detect the amount of grain.
