The results presented in this paper were focused on the easy development of cheap, sensitive and integrable spinel zinc ferrite (ZnFe2O4) thin film gas sensors for the detection of ethanol. ZnFe2O4 layers of about 450 nm thick were deposited by spray pyrolysis technique. The resulting films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Analysis confirmed the formation of monophasic spinel structured thin films with flat surface and dense microstructure consisting of nanosized grains. The sensor detects ethanol concentrations as low as 1 ppm and shows comparably fast behaviour of response and recovery.