This work provides the basis for a "fingerprint" analysis of the microstructure and the texture of anatase thin films by using Fourier transform infrared spectroscopy. For this, a formalism that reproduces the experimental spectra has been developed and its applicability is analysed for anatase thin films with different microstructure (columnar and porous, with varying degrees of compactness) and texture. The rather good agreement between calculated and experimental spectra observed in all cases demonstrated that a systematic use of this non-destructive technique can be very useful for the characterization of thin films. (c) 2006 Elsevier B.V. All rights reserved.