Abstract: A cosmetic of stable quality is produced by a method which comprises applying superposed electric waves severally on an aqueous part and an alcohol part or an oil part, then mixing the aqueous part with the alcohol part and/or the oil part, and subsequently applying the superposed electric waves on the resultant mixture. By this method, in spite of the absence of a surface active agent, the aqueous part and the alcohol part and/or the oil part are uniformly dissolved, dispersed, or emulsified in each other to produce a cosmetic lotion, a cosmetic milky lotion, or a cosmetic cream which remains stably for a long time.