To stop filling of grain accurately by detecting the load current value of a drive motor in a board for scattering grains through rotary action, comparing the detected load current value with a threshold level corresponding to the filling state and determining the filling state and then controlling operation/ stop of the drive motor.

When a filling button is turned on, a drive motor 10 is driven to turn a scattering board 13. Grains in a hopper are transferred through an elevator 6 and a lateral carrying machine 7 onto the scattering board 13 thence scattered around thus filling in a storing section 2. When the storing section 22 is filled with grains, the current (load current) being fed to the drive motor 10 is detected through a load current section attached to a motor drive circuit. The detected load current value is compared with a threshold level corresponding to a prestored filling state and the drive motor 10 is stopped when the threshold level is reached.