Thin film of tungsten oxide have been successfully fabricated from tungsten target by using reactive sputtering combine with lithoghraphy technology. The thickness, structures and morphology of the thin films have been investigated by α-step, XRD and FE-SEM. The gas sensing measurements of the WO3 thin film sensors indicate that these sensors have a high sensitivity and quick response behavior to C2H5OH. With the simple research method (using only two masks) and cheap materials, the results of this study have a lot of potential for applying C2H5OH gas. The result of this research application for control C2H5OH concentration . . .