A method for manufacturing aggregated resin particles, includes: preparing a microreactor that includes a first flow channel, a second flow channel, and a confluent flow channel, to which the first flow channel and the second flow channel merge; introducing a first fluid that contains resin particles dispersed therein into the first flow channel; introducing a second fluid that contains an aggregating agent into the second flow channel; feeding the first and second fluids so that a feed amount per unit time of the second fluid is greater than a feed amount per unit time of the first fluid, so as to form a laminar flow, in which the first fluid and the second fluid are merged, in the confluent flow channel; and forming aggregated resin particles by aggregating the resin particles.