PURPOSE: To eliminate a regular monitoring of a discharging work and enable other works to be efficiently carried out by a method wherein there are provided means for calculating a discharging time in reference to a grain discharging capability in its weight and a detected weight and a stop control means for stopping and controlling a discharging cooperating mechanism.

CONSTITUTION: Upon completion of drying operation, a discharging switch 24 is turned ON, internal grains are discharged to a discharging section such as a chaff removing machine. This turned ON of the discharging switch 24 causes a discharging shutter 47 to be opened and the circulating crops are flowed down at a discharging cylinder 46. A calculation control section 33 always reads detected weight W from each of weight sensors 44, 44..., calculates a discharging weight (w) per unit time in reference to a required time (t) and a total crop weight Wo upon completion of pre-read drying time and concurrently the calculation control section 33 calculates a time T required for discharging residual material. In this way, during discharging operation, a discharging and processing amount and a residual material discharging time T are alternatively displayed at a digital display section 26 in a specified time interval through a mode changing-over of the changing-over switch 48. An operator can improve an efficiency of other works in compliance with this display.