There is disclosed a process for producing a glycidyl ester of acrylic acid or methacrylic acid which comprises the steps of neutralizing acrylic acid or methacrylic acid with a carbonate or a bicarbonate of an alkali metal in an excess amount of epichlorohydrin while an oxygen-containing gas is blown into the liquid reaction system; subjecting water formed by the neutralization and epichlorohydrin to azeotropic distillation to discharge them outside the reaction system and to form an alkali metal salt of acrylic acid or methacrylic acid; adding a quaternary ammonium salt as a catalyst to the reaction system to react the alkali metal salt of the acid with the epichlorohydrin and thus synthesize the glycidyl ester of the acid; cooling the liquid reaction product while recovering part of the excess epichlorohydrin under reduced pressure; adding aqueous solution of an alkali hydroxide to the liquid reaction product to separate into aqueous layer and organic layer; adding a catalyst deactivator to the organic phase; and subsequently distilling the organic layer to separate the glycidyl ester of the acid while blowing an oxygen-containing gas into the organic layer. The above process makes it possible to efficiently produce a highly pure glycidyl ester of acrylic acid or methacrylic acid in high yield with minimized contents of impurities.