The present invention provides a novel stable oil-in-water microemulsion cosmetic composition. An oil-in-water microemulsion cosmetic composition according to the present invention contains: a dispersion medium which contains water and a divalent glycol； an oil component which is dispersed in the dispersion medium, while containing a silicone oil and a hydrocarbon oil； a carboxyl-modified silicone surfactant represented by formula 1； at least one compound which is in a liquid state at 25°C and has 16-22 carbon atoms, and which is selected from among higher alcohols and higher fatty acids； and a nonionic surfactant which has a polyoxyethylene chain, while having an HLB of 12-17. This oil-in-water microemulsion cosmetic composition is configured such that the average particle diameter of oil droplets is 150 nm or less. In formula 1, at least one of R1-R3 moieties is expressed by -O-Si(R4)3 wherein R4 represents at least one substituent selected from among alkyl groups having 1-6 carbon atoms and a phenyl group； in cases where not all of the R1-R3 moieties are the substituents, the rest may be the same or different and each represents a substituted or unsubstituted monovalent hydrocarbon group； A represents a linear or branched alkylene group which is represented by CqH2q wherein q represents an integer of 0-20； and M represents a metal atom or an organic cation.La présente invention concerne une nouvelle composition cosmétique en micro-émulsion huile dans eau stable. Une composition cosmétique en micro-émulsion huile dans eau selon la présente invention contient : un milieu de dispersion qui contient de l'eau et un glycol divalent ； un composant huileux qui est dispersé dans le milieu de dispersion et qui contient une huile de silicone et une huile hydrocarbonée ； un tensioactif siliconé modifié par carboxyle représenté par la formule 1 ； au moins un composé qui est à l'état liquide à 25 °C, qui comporte 16 à 22 atomes de carbone et qui est choisi parmi des alcools su
