which pass vertically therethrough and hardening it and laminating the porous body to one side of the humidity absorbing body of the same composition as the above embodiment 1 instead of the porous body of embodiment 4 the hygroscopic composite material was obtained by laminating an extrusion molded cement calcium silicate plate the average diameter of micropores 0 6 u03bc to the humidity absorbing body of the above embodiment 4 a hygroscopic composite material was made in which a polypropylene sheet of 20 u03bc thickness is bonded to the surface of the porous body of the above embodiment 4 instead of the porous body of the above embodiment 4 the hygroscopic composite material was formed by laminating a calcium silicate plate the average diameter of micropores 0 6 u03bc to the humidity absorbing body of the above embodiment 4 and by coating urethane resin on the calcium silicate plate at the rate of 10 g square shaku a zonotolite calcium silicate plate of 25 mm thickness was used as a hygroscopic material sold on the market the hygroscopic composite material was obtained by laminating filter paper average diameter of micropores 20 u03bc instead of the porous body of embodiment 1 to the humidity absorbing body of embodiment 1 in the above embodiments 1 7 and comparative examples 1 and 2 the.