PROBLEM TO BE SOLVED: To provide a method for manufacturing a stable oil-in-water type emulsified composition that comprises uniformly dispersed microparticles having a monodisperse particle size distribution.SOLUTION: The manufacturing method of the oil-in-water type emulsified composition comprises converting a composition comprising (A) a surfactant, (B) an oily component in a liquid state at 25°C and (C) water into a high-pressure fluid and emulsifying it by means of an atomizing apparatus equipped with a nozzle means for causing the high-pressure fluid to collide with each other and an introduction flow channel for introducing the high-pressure fluid into the nozzle means, where the nozzle means is equipped with a nozzle main body made of a highly hard material, the nozzle main body being provided with a flow channel for collision of the high-pressure fluids composed of a plurality of penetrating holes formed towards the radial direction from the outer peripheral surface of the nozzle main body and a guiding-out flow channel for guiding the fluids out after collision formed along the axis direction from a confluent point of the flow channels for collision, and is designed to introduce the high-pressure fluid introduced into the introduction flow channel to each opening at the end portion at the outer peripheral side of the flow channel for collision of the high-pressure fluids from the outer peripheral of the nozzle main body and where the length L1 from the opening at the end portion at the outer peripheral side of the flow channel for collision of the high-pressure fluids to the guiding-out flow channel is ranging from 0.1 mm to 1.5 mm and the cross-section area A2 of the guiding flow channel outside satisfies the relationship: 5A1&leA2&le50A1 to the total A1 of the cross-section of all of the flow channels for collision of the high-pressure fluids.COPYRIGHT: (C)2009,JPO&INPIT【課題】微小粒子が均一に分散し、単分散な粒子径分布で、安定な水中油型乳化組成物を製造する方法の提供。【解決手段】(A)界面活性剤、(B)25℃で液状の油性成分及び
