Yttria stabilized zirconia (YSZ) films have been characterized. The refractive index measured by ellipsometry is about 2.1. The breakdown electric field is greater than 4MV/cm for small area capacitors with a decrease for large area capacitors. This dielectric strength is weakly dependent on the film thickness within the range 0.2-1.lμm. The analysis of the 1MHz C(V) curves by the Terman method leads to a density of interface states of the order of 1012cm−2eV−1 in the middle of the bandgap with an increase near the conduction and the valence bands. The sensitivity of zirconia to the irradiations has been characterized by analysing 1MHz C(V). With or without electric field applied during the irradiations, the Flat-Band voltage shifts are lower for YSZ films than for thermal silicon dioxide films (2 times smaller).