To provide a method of measuring the supply quantity of a powdery and granular material capable of minimizing the measuring error without lowering the measuring accuracy.

In a measuring hopper 2 having a shutter 7 for supplying the powdery and granular material 6, when a weight of the measuring hopper 2 reaches the lower limit set value, the shutter 7 is opened to replenish the granular material 6, and when the weight of the measuring hopper 2 reaches the upper limit value, the shutter 7 is closed to stop replenishment of the powdery and granular material 6. In this method of measuring the supply quantity of the powdery and granular material 6, the measurement of the supply quantity is started after the predetermined time (t) passed from a time when the weight of the measuring hopper 2 exceeds the upper limit value to the maximum.