Abstract In this work, the temperature behavior of the adsorption porous silicon FET (APSFET) in the presence of different isopropanol vapors concentrations is investigated. Sensor current at different temperatures and concentrations of the sensed species is measured. Experimental data is analyzed it terms of possible mechanisms involved in the modulation of the sensor current. The temperature dependence of the sensitivity suggests that the mechanism involved in the sensing is some kind of physical adsorption of the sensed species by the porous layer. The sensitivity of the device does not seem to be significantly affected by aging effects. © 2004 Elsevier B.V. All rights reserved. Keywords: Gas sensor; Porous silicon; Polar molecules; Alcohol substances