SrS thin films were deposited by electron beam evaporation on heated silica substrates. The optical properties of the layers - complex refractive index and optical band gap - were derived from optical transmission spectra, measured by means of UV-VIS-NIR spectrophotometry. The influence of post-deposition annealing by rapid thermal processing (RTP) was studied. X-ray powder diffraction (XRD) was used to study the film crystal structure and preferential orientation.