Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic panels. Moisture adsorption and desorption of porous materials were investigated and hydrothermal method was applied to fabricate panels. Cheolwon diatomite and Pohang zeolite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Correlation coefficient between surface area and moisture adsorption content of porous materials was 0.93. Moisture adsorption contents were influenced by surface area and pore volume of panels, and surface area more effected on moisture adsorption. Correlation coefficient between surface area and moisture adsorption content of panels was 0.86. Moisture adsorption content of panel with 10% Pohang zeolite was $180;g/m^2$ and that of 10% Cheolwon diatomite was $170;g/m^2$. Moisture desorption content of panel with 10% Pohang zeolite was $105;g/m^2$. Moisture adsorption contents of panel with porous materials were higher than that of panel without porous materials.