PURPOSE: To enable the control of a yield by providing an atomizer and a rotary disc in an emulsification tank, and forming an emulsification plane on the surface of the rotary disc.

CONSTITUTION: An atomizer 2 is inserted in an emulsification tank 1 from above and is thus provided therein. The atomizer 2 consists of a rotary atomizing head 3 and a motor 4. A rotary disc 12 is provided below the head 3 and the disc 12 is fixed and provided to the hollow revolving shaft 13A of a motor 13 as a rotating and driving means and is driven to rotate by the motor 13. A supply pipe 14 for a continuous phase liquid is inserted into the shaft 13A and one end of the pipe 14 opens toward a well 15 formed by recessing the central part of the disc 12. The other side is connected, via a pump 16, to a tank 17 for the continuous phase liquid. An emulsification plane 18 is formed in continuation with the well 15 on the surface of the disc 12 by which the continuous phase liquid is made into a thin film.