The conductivity of silver bromide emulsion microcrystal was measured using microwave technique. The dielectric loss method has been conventionally used for the measurement of electric conductivity of the interstitial silver ion. However, it is necessary to take the influence by crystal form into consideration by this method. By using microwave technique, it is thought that it is not influenced by crystal form. In this research, it measured by changing particle size and temperature to the pure cubic and octahedral AgBr microcrystals. And from this result, we got the activation energy, E=0.32eV