PURPOSE: To obtain the titled compound useful as a production intermediate for pharmaceuticals, intermediate for organic compounds for photographic use, etc., under mild condition at a low cost in high yield, by reacting a hydroquinone diester with a base, thereby selectively cleaving one of two ester bonds.

CONSTITUTION: A hydroquinone-monoester of formula II (e.g. hydroquinone monopivalic acid ester) can be produced by reacting (A) a hydroquinone diester of formula I [R1 is R3 (R3 is aliphatic group), R3-O-, R3(R4)N- (R4 is aliphatic group or aromatic group), R5-O- (R5 is same as R3), R6-S- (R6 is aliphatic, aromatic or heterocyclic group); n is 0W4; when n≥2, plural R2 groups may be the same or different or together form a ring] (e.g. hydroquinone pivalic acid ester) with (B) a base (especially preferably metal hydroxide, metal alcoholate or ammonia water) preferably at -20W+50°C.