PURPOSE: To enable blowing of a large quantity of fine powdered coal and to stabilize blast furnace operation by blowing the fine powdered coal having a reaction rate to CO2 in combustion residue in the specific combustion test higher than that of coke charged and used into the blast furnace.

CONSTITUTION: The combustion test to the optical powdered coal is executed under the equal combustion condition as the combustion condition in raceway in the blast furnace to the powdered coal blown from tuyere in the blast furnace. The powdered coal having a reaction rate to CO2 gas in the combustion residue obtd. with this higher than that of the coke charged and used in this blast furnace, is selected and blown. Further, the powdered coal having ≥70(m2/g) specific surface area in the above combustion residue may be blown. When this powdered coal reaches bulky zone in the blast furnace under condition of imperfect combustion powdered coal, this is reacted with the coke at a high rate and consumed. By this method, deposition of the imperfect combustion powdered coal in the bulky zone is prevented and a large quantity of fine powdered coal can be blown and the blast furnace operation can be stabilized.