We have developed a novel thermoelectric gas sensors based on bismuth telluride thin films.These sensors were employed for sensing different concentrations of H_2 gas.Radio frequency (R.F.) magnetron sputtering was employed to deposit the bismuth telluride (Bi_2Te_3) thin films.The morphology of such thin films was investigated and responses of the thermoelectric devices to H_2 were studied. We have developed a novel thermoelectric gas sensors based on bismuth telluride thin films. The sensors were employed for sensing different concentrations of H_2 gas. Radio frequency (RF) magnetron sputtering was employed to deposit the bismuth telluride (Bi_2Te_3) thin films. such thin films was investigated and responses of the thermoelectric devices to H_2 were studied.