To provide a flour milling machine for grains capable of always maintaining a constant feed rate of the grains sent from a raw material hopper to a stone mill and easily adjusting the feed rate.

The flour milling machine for the grains equipped with the raw material hopper 21 and a raw material feed pipe 34 to feed the grains supplied into the hopper 21 to the stone mill 22 through the outlet 26 of the hopper 21 is provided with a shutter 27 for adjusting the feed rate to send the grains by a predetermined rate to the outlet 26 of the hopper 21 while the raw material feed pipe 34 is provided with an opening and closing valve 42 to interlock the opening and closing movement of the valve 42 with the rotation of the stone mill 22.