Abstract: To provide a water separation device and a water separation method in which an object in a water dispersion organic solvent is not adsorbed and neither contaminated, and water can be separated and removed in a short period of time irrespective of specific gravity of an organic layer in the water separation organic solvent, characterized in that a water separation membrane is provided on a rising surface between a lower end and an upper end of a tubular member, and a water dispersion organic solvent is filtrated by the water separation membrane to thereby separate water to cause the organic solvent to pass through.