Temperature and humidity dependence on electric conductivity is investigated for two kinds of antimonic acids, which have a cubic structure (c-SbA) and a monoclinic structure (m-SbA). The conductivity of m-SbA at 296 K is lower and more sensitive to humidity than that of c-SbA. The conductivity of c-SbA increases with increasing temperature, but, that of m-SbA decreases with increasing temperature under the saturated water vapor pressure in the temperature range of 296-353 K. FTIR measurements show the existence of motion-restricted water in m-SbA. The amount of adsorbed water in c-SbA is larger than that in m-SbA. The difference in conductivity between c-SbA and m-SbA is closely related to the state of hydroxyl groups and water molecules in both antimonic acids.