We performed an investigation by atomic force microscopy (AFM) of the hydrophilicity of TiO2 thin films obtained by radio frequency magnetron sputtering deposition (RFMSD) and plasma enhanced chemical vapor deposition (PECVD). On the basis of a theoretical model of the capillary and superficial tension force of the capillary water bridge formed at tip-sample contact, it is proved that AFM measurements in the atmospheric air of the tip-sample adhesion force provide information about the sample surface hydrophilicity at the microscopic level with a resolution of a few nanometers. Macroscopically, the film hydrophilicity was characterized by a water drop contact angle that, as a result of UV irradiation in atmospheric air, decreased from 60 degrees to 20 degrees for RFMSD films and from 60 degrees to 4 degrees for PECVD films. The AFM measurements revealed that the UV-induced macroscopic changes in the film hydrophilicity corresponded to an increase of the tip-sample adhesive force on the film surfaces. Very inhomogeneous adhesive force distributions were observed for RFMSD films, while even distributions were observed for PECVD films. Fluctuations in sample surface curvature due to grain occurrence on the film surface could not account for the wide spread of the adhesive force values noticed for RFMSD films, and such force distributions were ascribed to an uneven arrangement of oxygen bridging sites on the film surface. The relatively homogeneous distributions of the adhesive force values on the PECVD film surface were characterized by Gaussian probabilities of occurrence.