A comparative study of the structural features of zinc 2,9,16,23-tetra-tert-butylphthalocyanine films (ZnPc(tBu)4) obtained by vacuum thermal deposition and spin coating techniques is performed. By powder X-ray diffraction, 2D GIXD, and optical absorption spectroscopy it is shown that ZnPc(tBu)4 films obtained by the spin coating technique consist of a disordered α-phase with small crystallites. After annealing at 200 °C for 3 h the films transform into the β-phase, with crystallite sizes increasing, however, they remain disordered relative to the substrate surface. On heating under the same conditions, the ZnPc(tBu)4 films obtained by thermal vacuum sublimation transform from the weakly oriented low-temperature α-phase into the oriented β-phase. Dependences of a chemiresistive sensor response of the ZnPc(tBu)4 films to ammonia (10-50 ppm) are investigated depending on the preparation and annealing methods of the films.