58% semi-crystalline thin parylene-VT4 (-H2C-C6F4-CH2-)(n) films, have been investigated by dielectric spectroscopy for temperature and frequency ranges of [-120 to 380 degrees C] and [0.1-10(5) Hz] respectively. The study comprises a detailed investigation of the dielectric constant, dielectric loss and AC conductivity of this fluoropolymer. Dielectric behavior of parylene-VT4 is represented by a low dielectric constant with values in the range of 2.05-2.35 while the dielectric losses indicate the presence of two relaxation processes. Maxwell-Wagner-Sillars (MWS) polarization at the amorphous/crystalline interfaces with activation energy of 1.6 eV is due to the oligomer orientation. Electrical conductivity obeys to the well-known Jonscher law. The plateau in the low frequency part of this conductivity is temperature-dependent and follows an Arrhenius behavior with activation energy of 1.17 eV (deep traps) due to the fluorine diffusion. Due to its thermal stability with a high decomposition temperature (around 400 degrees C under air and 510 degrees C under nitrogen) and due to its good resistivity at low frequency (10(15)-10(17) Omega m(-1)), parylene-VT4 constitutes a very attractive polymer for microelectronic applications as low k dielectric. Moreover, when parylene-VT4 is subjected to an annealing, the dielectric properties can be still more improved. (C) 2013 Elsevier B.V. All rights reserved.