To provide a flour mill of grain, a seed, and a hard resin which can uniformly feed even a stock with bad fluidity over the whole roll width to be effectively operated and more highly effectively crush an ordinary stock.

The flour mill, which has a stock hopper 1 with an inlet cylinder 1a, a stock feed roll 2, a feeder gate open/shut means 4 for opening and shutting a feeder gate 3, and a pair of milling rolls 5, is equipped with a level sensor 6 for measuring a stock level Aa in an noncontact state and two load cells 7 for measuring a stock A in contact therewith, so that the measured values are input in a control means 9, respectively, by which a space between the stock feed roll and the feeder gate and a gap of the pair of milling rolls are controlled.