To obtain a grain supply changeover apparatus capable of charging grain to be sorted in an unhulled grain housing funnel arranged at a suitable position of an impeller-shaped hulling machine in the same way as usual hulling work only by the simple operation of a handle formed so as to protrude to the outside of the hulling machine even in the case of readjustment work of unhulled rice mixed unpolished rice or wheat sorting work in the hulling machine.

In the grain supply changeover apparatus, a changeover valve 22 is disposed on the way of an unhulled rice supply passage 10 for supplying grain to be sorted to a dehulling fan 16 from an unhulled rice housing funnel 8 and a changeover fulcrum shaft to which the changeover valve 22 is fixed is further protruded to the outside of the hulling machine and a changeover handle 21 is fixed to the leading end part of the fulcrum shaft and, by revolving this changeover handle 21, a route for allowing the grain supplied to the unhulled rice housing funnel 8 to flow in the dehulling fan 16 and a route for allowing the same to directly flow in a diffusion chamber 12 in which unpolished rice or chaff after dehulling treatment is charged are changed over.