To prevent the accumulation of spillage into a vertical pulverized coal machine of a coal firing boiler when measuring a spillage quantity of a spillage discharge device applied to this pulverized coal machine.

The spillage (foreign matter) generated at the time of pulverizing coal by a pulverizing table 1 and rollers 2 falls from the outer periphery onto a scraper 3 and accumulates in a spillage hopper 5 by passing a spillage chute 4, a spillage hopper inlet valve 6 and a flexible joint 9. At the time of measuring the spillage quantity, an outlet valve 7 is closed by the signal of a control section 11 and the spillage quantity is measured by a load cell 8 at every specified time. This signal is inputted to the control section 11 which continuously monitors the change in the spillage quantity. The outlet valve 7 is thereafter opened to discharge the stored spillage. The inlet valve 6 may be held open or be closed at the time of discharge. Since the spillage quantity is continuously measured by the control of the spillage 11, the spillage does not accumulate in the pulverized coal machine 10.