Thin layers of tin acetyl acetonate (SnAcAc) were deposited by the laser ablation deposition (LAD) method onto potassium bromide tablets. FTIR and X-ray photoelectronspectroscopy (XPS) spectra of these layers were investigated to describe changes in chemical composition during the deposition and following a thermal activation process. The main interest was focused on the formation of systems containing conjugated double bonds, tin dioxide (SnO2), tin suboxides (SnOx; x < 2), and salts (especially carboxylates). These phases play an important role in the use of LAD-deposited acetyl acetonates as active layers of chemical sensors.