Provided is a superheated steam sterilization apparatus capable of continuously sterilizing a large amount of grain and of capable of eliminating uneven application of superheated steam even when a large amount of grain is loaded thereinto. A superheated steam sterilization apparatus according to one embodiment of the present invention includes: a horizontal cylindrical part including one end formed with a supply port for supplying an object to be sterilized and an opposite end formed with a discharge port for discharging a sterilized object a rotating shaft part rotatably disposed in the horizontal cylindrical part, and including a helical screw configured to transfer the supplied object to be sterilized and an agitating member including a plurality of agitating blades configured to agitate the object to be sterilized a plurality of superheated steam nozzles disposed above the horizontal cylindrical part a superheated steam box disposed on the horizontal cylindrical part, divided into a plurality of sections along an axial direction, and configured to temporarily store superheated steam supplied from the superheated steam nozzles and a steam outlet for applying superheated steam stored in the superheated steam box to the object to be sterilized which is transferred and agitated in the horizontal cylindrical part.
