The present invention provides a method for producing lipid particles that have a desired particle diameter, the method comprising: (A) a step for preparing, in a first mixing region, a primary dilution by mixing a first solution containing a lipid and an alcohol with a second solution containing water; (B) a step for feeding the primary dilution from the first mixing region to a second mixing region through a liquid feed pipe within a prescribed time; and (C) a step for preparing a secondary dilution by mixing the primary dilution with a third solution containing water in the second mixing region, wherein the steps (A)-(C) are continuously carried out, and the particle diameter of the lipid particles is controlled by adjusting at least one condition selected from the group consisting of the concentration of the alcohol and the concentration of the lipid in the primary dilution, the prescribed time, and the temperature during mixing.