The present invention relates to an optically active .alpha.-substituted carboxylic acid derivative represented by the general formula (I): ##STR1## (wherein R.sub.1 is a hydroxyl group, ##STR2## R.sub.2 is a methyl group or a chlorine atom; R.sub.3 is a hydrogen atom or an alkyl group with 1-6 carbon atoms; n is an integer of 1 or 2; and * represents an asymmetric carbon atom, provided that R.sub.2 is a chlorine atom when R.sub.1 is a hydroxyl group); and a method for producing the optically active .alpha.-substituted carboxylic acid derivative represented by the general formula (I) and antipodes thereof using a culture, cells or a material obtainable from cells of a microorganism having an ability to asymmetrically hydrolyze ester bonds. The optically active .alpha.-substituted carboxylic acid derivatives and antipodes thereof provided by the invention are useful as raw materials for various liquid crystals and as synthetic intermediates for various optically active medicines or agricultural chemicals.