A method for producing fine particles by allowing a dissolved solution prepared by dissolving a material for forming the fine particles into a solvent with the use of a dissolution auxiliary agent and a poor solvent for varying a solubility of the material for the fine particles to mix each other, wherein the fine particles are generated by flowing the dissolved solution, the poor solvent and a dispersing agent solution for dispersing the fine particle through respectively independent supply channels to join each other at one joining channel and flow together. A decomposition and deterioration caused by a reaction between the dispersing agent and a component of the solution is suppressed and fine particles with high monodispersing property can be produced.