To provide the supply shutter of an automatic grain weighing machine of which the shutter can be closed even after weighing operation, in order to solve the problem that a conventional automatic grain weighing machine has no mechanism to close its shutter during the time when no weighing operation is carried out and the shutter is left open after weighing operation, so that the residual rice is scattered upon reopening the operation.

According to the supply shutter, the shutter pivotally attached to the supply inlet of a storage tank and a shutter arm coupled to a reciprocating member are engaged and disengaged with each other via a solenoid to open, partly open, and close the supply inlet. The shutter can be closed by turning off a power switch to electrify the solenoid, making retreat the shutter arm via the reciprocating member.