Abstract: Disclosed is an ascorbic acid derivative or a salt thereof wherein at least one of hydrogen atoms in hydroxy groups at the 2-position and the 3-position of ascorbic acid is substituted by R—O—CH2—CH(OH)—CH2—, R—O—CH2—CH(CH2OH)—, R—CH(CH2OH)—, R—CH(OH)—CH2— (wherein R represents an alkyl group, an alkenyl group or a phenyl group), or a hydroxycyclohexyl group. Also disclosed is a method for producing an ascorbic acid derivative or a salt thereof, which is characterized by reacting ascorbic acid with an epoxy compound such as an alkyl glycidyl ether, an epoxy alkane or an alicyclic epoxy.