PURPOSE: To provide the device which automatically mixes more than two kinds of liquid with the prescribed compounding ratio.

CONSTITUTION: The device is provided with more than two measure vessels 20 which accepts the liquid before being mixed, stirring vessel 45 which accepts the liquid from the vessel 20 and mixes it, stirrer 60 which stirs the liquid in the vessel 45, liquid measuring means 35 which measures the height of the liquid surface in the vessels 20 and 45, and control means 40 which controls the liquid amount in the vessels 20 and 45 based on the information on the liquid surface height from the means 35.