PURPOSE: To simplify the constitutional mechanism of an apparatus for supplying a chemical agent, to maintain the continuous stable operation of the apparatus, and to reduce the total costs.

CONSTITUTION: The constitutional mechanism of an apparatus for supplying a chemical agent is constituted so that the chemical agent is fed in the following order: storage tank 11 → manual slide gate 12 → detection tank 13 → quantitative rotary valve 14 → transportation pipe 15. Aeration equipment 16 and an air knocker 17 are installed in the lower part of the storage tank 11, the aeration equipment 16 and a clogging detection powder surface meter 18 are installed in the lower part of the detection tank 13, and dry compressed air is injected periodically to the lower part of the quantitative rotary valve 14. In this way, the simplification of the constitutional mechanism, the maintenance of the continuous stable operation, and the reduction of the total costs can be attained.