A technique has been developed for examining the bulk electrical properties of dry zirconium dioxide films. It has been used to determine the dielectric loss spectra of films formed by steam corrosion, and by anodization of Van Arkel zirconium. The most marked feature is a loss peak found for thermal films grown on pickled surfaces. This does not occur with anodized specimens or electropolished specimens and is postulated to be due to a fluorine‐containing dipole. The dipole relaxes with an activation energy of 0.72 ± 0.04 ev. An interpretation of the data suggests a lower limit of concentration of fluorine ions per cubic centimeter in films of about 1500Aå thickness. Anodic films show low loss curves consistent with near‐stoichiometric structure.