PURPOSE: To reduce both installation area and operating cost by providing at least one of plural storage silos arranged parallel as a receiving silo, vertically dividing an inner space thereof with partition plates and forming the space into plural receiving tanks.

CONSTITUTION: A receiving silo 8 is vertically divided with partition plates 11 to form a receiving tank 13 for temporarily storing raw material unhulled rice with the partition plates 11 and sidewalls 12. Harvested threshed materials with a high moisture content are fed to the receiving silo 8, charged into one of the receiving tanks 13, fed to a dryer 22, dried and then fed to a storage silo 15 to carry rotation until the grains are conditioned to a prescribed moisture content.