Zinc selenide (ZnSe) thin films (d = 0.11-0.93 mu m) were deposited onto glass substrates by the quasi-closed volume technique under vacuum. Their structural characteristics were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). The experiments showed that the films are polycrystalline and have a zinc blende (cubic) structure. The film crystallites are preferentially oriented with the (111) planes parallel to the substrate surface. AFM images showed that the films have a grain like surface morphology. The average roughness, R-a = 3.3-6.4 nm, and the root mean square roughness, R-rms = 5.4-11.9 nm, were calculated and found to depend on the film thickness and post-depoisition heat treatment. The spectral dependence of the absorption coefficient was determined from transmission spectra, in the range 300-1400 nm. The values of optical bandgap were calculated from the absorption spectra, E-a = 2.6-2.7 eV. The effect of the deposition conditions and post-deposition heat treatment on the structural and optical characteristics was investigated. (C) 2007 Elsevier B.V. All rights reserved.