The purpose of this invention is to provide a method for stabilizing a cosmetic over a long period of time. In order to achieve this purpose, this invention provides a method for improving the storage stability of a cosmetic, the method including blending a compound represented by the following general formula (1).(In formula (1), R1 represents a group represented by general formula (2) or a hydrocarbon group having 2 or 3 carbon atoms.)(In formula (2), R2 represents an alkylene group having 1 to 3 carbon atoms, and n represents an integer of 0 or 1.)