A method for producing ceramic microparticles, characterized in that each of a ceramic raw material solution that is obtained by mixing and/or dissolving at least one ceramic raw material in a basic solvent, or a ceramic raw material solution that becomes basic after the ceramic raw material is mixed with and/or dissolved in a solvent, a solvent for separating ceramic microparticles, and at least one acidic substance is prepared, and a step of separating ceramic microparticles is comprised that: at least two fluids are used as fluids to be processed, of these, at least one fluid is a fluid which contains the ceramic raw material solution and at least one fluid other than the fluid which contains the ceramic raw material solution is a fluid which contains the solvent for separating the ceramic microparticles, the fluid which contains the ceramic raw material solution is mixed with the fluid which contains the solvent for separating the ceramic microparticles in a thin film fluid formed between at least two processing surfaces (1, 2) which are disposed in a position facing each other so as to be able to approach to and separate from each other, at least one of which rotates relative to the other thereby separating the ceramic microparticle, and a contacting step is comprised that the fluid which contains the separated ceramic microparticles obtained in is mixed with the fluid which contains the acidic substance introduced from an opening provided on at least any one of the at least two processing surfaces (1, 2) into between the at least two processing surfaces (1, 2), wherein the contacting step is, after the separating step, carried out continuously, wherein the acidic substance is contacted and reacted with the fluid which contains the separated ceramic microparticles in the thin film fluid, wherein the fluid which contains the separated ceramic microparticles is basic, and a heat of reaction that is generated by mixing the fluid which contains the separated ceramic microparticles with the fluid which contains the acidic substance is utilized to control a crystallinity of the ceramic microparticle, wherein the acidic substance is sulfuric acid. a step of separating ceramic microparticles is comprised that: at least two fluids are used as fluids to be processed, of these, at least one fluid is a fluid which contains the ceramic raw material solution and at least one fluid other than the fluid which contains the ceramic raw material solution is a fluid which contains the solvent for separating the ceramic microparticles, the fluid which contains the ceramic raw material solution is mixed with the fluid which contains the solvent for separating the ceramic microparticles in a thin film fluid formed between at least two processing surfaces (1, 2) which are disposed in a position facing each other so as to be able to approach to and separate from each other, at least one of which rotates relative to the other thereby separating the ceramic microparticle, and at least two fluids are used as fluids to be processed, of these, at least one fluid is a fluid which contains the ceramic raw material solution and at least one fluid other than the fluid which contains the ceramic raw material solution is a fluid which contains the solvent for separating the ceramic microparticles, the fluid which contains the ceramic raw material solution is mixed with the fluid which contains the solvent for separating the ceramic microparticles in a thin film fluid formed between at least two processing surfaces (1, 2) which are disposed in a position facing each other so as to be able to approach to and separate from each other, at least one of which rotates relative to the other thereby separating the ceramic microparticle, and a contacting step is comprised that the fluid which contains the separated ceramic microparticles obtained in is mixed with the fluid which contains the acidic substance introduced from an opening provided on at least any one of the at least two processing surfaces (1, 2) into between the at least two processing surfaces (1, 2), wherein the contacting step is, after the separating step, carried out continuously, wherein the acidic substance is contacted and reacted with the fluid which contains the separated ceramic microparticles in the thin film fluid, wherein the fluid which contains the separated ceramic microparticles is basic, and a heat of reaction that is generated by mixing the fluid which contains the separated ceramic microparticles with the fluid which contains the acidic substance is utilized to control a crystallinity of the ceramic microparticle, wherein the acidic substance is sulfuric acid.