Gas monitoring devices consisting of metal oxide thin films have been very widely applied as chemical sensors. They find profound use towards detection of toxic pollutant gases and organic vapors. They provide beneficiary merits as large scale commercial sensors owing to their low price, small size, high sensitivity and consume very low power. Ethanol is one of the most commonly and extensively used alcohol, both in the fields of research and industrial applications. There is an imminent need to develop sensors for its detection with very sensitivity. In this study, Zinc oxide nanoparticles were prepared by a suitable soft chemical method. ZnO thick films were prepared from these nanoparticles by dip coating method. ZnO thick films are coated on an Alumina substrate and the sensor is tested for ethanol for 50 ppm at various temperatures. The sensor was found to operate with maximum efficiency at an optimum temperature of 350°C.