PURPOSE: To obtain 1,4-benzoquinone in high purity and yield using industrial easy operation by dropping an aqueous solution of an oxidizing agent into hydroquinone in the presence of a metallic vanadium salt, dilute sulfuric acid and an inert organic solvent.

CONSTITUTION: An aqueous solution of an oxidizing agent such as sodium chlorate is dropped into hydroquinone, dilute sulfuric acid, a metallic vanadium salt (vanadium pentoxide) and an inert organic solvent to carry out oxidation reaction and afford 1,4-benzoquinone. A high purity and yield can be attained using simple operation without requiring strict control of reaction temperature or reaction time according to the aforementioned method. The catalyst can be directly reutilized. The resultant 1,4-benzoquinone is extremely useful as an intermediate for medicines, agricultural chemicals, dyes, etc., polymerization inhibitor, stabilizer, etc., for monomers.