PURPOSE: To quantitatively feed a chemical agent which is required to be handled with care owing to its toxicity and stimulation to an intended part in a direct and safe manner by fixing a connector to one end of a hose or the like in an airtight manner, and connecting the connector to a pump of a chemical feeding device through a joint.

CONSTITUTION: A container 4 loaded on a carrying type frame 7 is set to the lower part of a chemical feeding device 1 with its opening part 4A being located immediately below a connecting part of a joint 3, and this container 4 is locked to a locking member 8 provided on a pillar 9. A cap is removed to open the opening part 4A, and a cylindrical body 2B of a feeding set 2 is inserted into the opening part 4A, and then, a connector 2A is inserted into the connecting part of the joint 3 and connected in a single operation. A small opening part 4B of the container 4 is opened, and the chemical level 5A in the container 4 is detected by a level sensor 10, and displayed on a display part, and the driving of a pump 13 is controlled. When the chemical level 5A reaches the prescribed position, the feeding of the chemical is stopped.