The dielectric properties of lead zirconate titanate [PZT, Pb(Zr 0.3Ti0.7)O3] films, prepared by aerosol deposition (AD), were measured in the millimeter wave and THz range. Millimeter wave spectroscopy was applied for measurement in the frequency range from 45 to 80 GHz, and far-infrared Fourier transform measurements from 120 GHz to 20 THz was carried out. Spectroscopic data were analyzed with combination of Debye model with a distribution of Debye relaxation frequencies and harmonic oscillators. We clearly observed that the Debye relaxation took place below several tens GHz for annealed AD films. Combination of millimeter wave and THz spectroscopy was effective measurement technique for dielectric properties of ferroelectric materials at over millimeter wave range.