The present invention provides a method for obtaining O/W emulsions by emulsifying various to-be-emulsified material without the use of any organic solvent, and drying and making into powder the O/W emulsion. The invention relates to a method for producing an O/W emulsion including after preliminarily dispersing a to-be-emulsified material and an interfacially active organic compound in water, heating the preliminary dispersion to a temperature equal to or higher than the melting point of the to-be-emulsified material and equal to or higher than the phase transition temperature of a self-assembled product of the interfacially active organic compound in the absence of an organic solvent, and performing emulsification under a pressure.
