To obtain a solid high-molecular electrolysis type humidity exchange module in which dust or the like floating in the air is prevented from being thrown to an electrolytic reaction surface to always keep clean the electrolytic reaction surface and enable operation and the backflow of steam of power feed stoppage is prevented to restrain humidity deterioration.

A pair of selective steam permeable membranes 52a, 52b are fitted so that they close the openings on both sides of a frame body 55, and a solid high-molecular electrolysis element 51 is fitted so that it separates a closed space constituted of the frame member 55 and the pair of the selective steam permeable membranes 52a, 52b into a first and second closed spaces 54a, 54b to constitute a unit cell 30. A can body 71 having vent pipes 72a, 72b in the lower and upper parts thereof is fitted so that it covers the selective steam permeable membrane 52b to form a third closed space 70 outside the second closed space 54b, and an electric heater 73 is arranged in the third closed space 70.