A method of producing polycarbonate-based polymer microparticles including forming an emulsion in a system in which a polycarbonate-based polymer (A), a polymer (B) different from the polycarbonate-based polymer (A) and an organic solvent (C) are dissolved and mixed together and which causes phase separation into two phases of a solution phase having the polycarbonate-based polymer (A) as its main component and a solution phase having the polymer (B) different from the polycarbonate-based polymer (a) as its main component, and contacting a poor solvent for the polycarbonate-based polymer (A) with the emulsion at a temperature of 80° C. or higher to thereby precipitate microparticles of the polycarbonate-based polymer (A).