The invention provides a method for producing an epoxy compound by hydrogen peroxide using an organic compound having a carbon-carbon double bond as a raw material, wherein a by-product is suppressed from being generated and the epoxy compound is produced in a high yield. In particular, the invention provides a method for producing an epoxy compound involving oxidizing a carbon-carbon double bond in an organic compound with hydrogen peroxide in the presence of a catalyst, wherein the catalyst comprises a tungsten compound; a phosphoric acid, a phosphonic acid or salts thereof; and an onium salt having an alkyl sulfate ion represented by formula (I) as an anion: wherein R1 is a linear or branched aliphatic hydrocarbon group having 1 to 18 carbons, which may be substituted with 1 to 3 phenyl groups.