To provide an organic solvent dehydration device, which achieves continuous purification of an organic solvent, and can efficiently and stably eliminate water from a large quantity of organic solvent without basically needing the replacement of a dehydration material.

An organic solvent dehydration device is configured to dehydrate and eliminate water contained in a treatment object organic solvent by introducing the treatment object organic solvent containing water into a dehydration material 11 to contact therewith. The dehydration material 11 is a cation exchange resin having a styrene-divinyl benzene copolymer as a base structure with a carboxylic or sulfonic group as a functional group, and having a saturated moisture content of 20-42 wt.%. The organic solvent dehydration device has: a dehydration tank 15 filled with the dehydration material 11; a treatment object organic solvent introduction line 13 for introducing the treatment object organic solvent into the dehydration tank 15; a decompressor 24 that decompresses the interior of the dehydration tank 15; and a desorbed gas discharge line 22 for discharging from the dehydration tank 15 a gas desorbed within the dehydration tank 15 and introducing it to the decompressor 24.