Provided is an emulsion including an oil-based component having a fine dispersion particle diameter and having good long-term stability. An O/A-type emulsion having an oil-based component dispersed in a polyvalent alcohol phase is obtained by mixing a fatty acid ester and an acyl amino acid and/or a salt thereof, at a specific ratio into a trivalent or higher-valency polyvalent alcohol and by adding the oil-based component to the mixture while stirring. The fatty acid ester is selected from a group comprising a polyglycerine fatty acid ester, a sorbitan fatty acid ester, a polyoxyethylene sorbitan fatty acid ester, and a mixture of these. An oil-in-water emulsion is obtained by adding the O/A-type emulsion to an aqueous medium while stirring.