To provide a water-absorbent film showing an improved water vapor barrier property and capable of adjusting humidity of both sides of the film by forming a water-absorbent layer since water existing on the outside or in the inner side of the film can not be treated.

The water-absorbent film capable of adjusting humidity and having the water vapor barrier property has a water-absorbent layer containing a water absorbent agent as a major component and a vapor deposition thin film layer of an inorganic oxide formed on it, both layers being mounted on at least one surface of a plastic film base material.