The invention relates to a method and an apparatus for dewatering mixture of ethanol and water. The method comprises steps for feeding mixture of ethanol and water (1) into an evaporator (2), evaporating said mixture of ethanol and water (1) and feeding a stream of vaporized mixture of ethanol and water (3) to a vapor recompression unit (4), pressurizing vaporized mixture of ethanol and water (3) in the vapor recompression unit (4) and feeding a stream of pressurized vaporized mixture of ethanol and water (5) to a membrane unit (6), and dividing said stream of pressurized mixture of ethanol and water (5) in to a stream of mixture of ethanol and water (8) and into a stream of dewatered mixture of ethanol and water (7).