This work aims to analyze the effects of dielectric materials and its characteristics in electric fields. Considering the field propagation inside the dielectrics and its permittivity dependency, were done experimental tests, in order to observe the electric fields perturbations in a presence of wood. The tests were done in half anechoic chamber of Fiat Automveis, and the results pointed to a field raise in the measure point, in detriment to the field measured in absence of this material. Finally, were done simulations which could confirm the dielectric expected influences. Also, here were discussed the impacts due to the field alterations in the electromagnetic compatibility experiments.