PURPOSE: To increase ventilation rate and enable continuous pulverizing for a long time by forming a branch pipe, connected to an exhaust blower through a settling hopper, midway in a pneumatic transportation pipe for taking out powder product.

CONSTITUTION: An upward branch pipe 8 is formed midway in a pneumatic transportation pipe 3 through which powder product reduced to powder in a pulverizer 1 is transported to a holding cyclon 4 and a holding bag filter 5 by absorption power. Furthermore, the branch pipe 8 is connected to an exhaust blower 10 through a settling hopper 9. As a result, the blowers both 6 and 10 being operated, the flow rate of air passing in the pulverizer 1 increases by the amount corresponding to the absorption increase by the blower 10, compared to the flow rate by the operation of only the blower 6. This ventilation sufficiently cools down the blades of the pulverizer, materials to be pulverized, etc.; thereby materials in hot and melting state can be pulverized continuously for a longer period.