A method of manufacturing resin particles uses a microreactor to mix first and second stock solutions, and to aggregate resin fine-particles to obtain resin particles. The microreactor includes stationary and rotating discs that are two discoid discs and that are disposed so that a gap is formed between circular surfaces of the two discs when the resin particles are manufactured, a first stock solution feed part that feeds the first stock solution from an end of the gap into the gap, and one or more second stock solution feed parts that are formed at the opposite side of the first stock solution feed part based on the center of the circular surface of the stationary disc by spatially connecting top and bottom surfaces of the stationary disc, and that feed the second stock solution containing an aggregating agent from the top surface side of the stationary disc to the gap.