PURPOSE: To decrease time lag and failure of a product when liq. agents being different from each other are mixed at a specified ratio.

CONSTITUTION: A container 12 and a container 13 respectively storing a liq. agent A and a liq. agent B being different each other and a measuring means consisting of an electronic balance 2 and an electronic balance 3 wherein these containers 12 and 13 are respectively placed and the wt. of the liq. agent A and the liq. agent B are respectively measured, are provided. In addition, an operating means wherein the outputs from the measuring means consisting of the electronic balances 2 and 3 are detected and the mixing ratio (X) of the liq. agent A and the liq. agent B is operated by the d1fference between each of the present wt. of the liq. agents A and B based on the wt. of the liq. agents A and B before a specified time and a feeding vol. controlling means wherein each of quantitative extrusion pumps 9 and 10 feeding respectively the liq. agents A and B each stored in the containers 12 and 13, is independently controlled by the output of the operating means, are provided.