Impedance spectroscopy (IS) was to analyze the dielectric behavior of cross-linked polyethylene (XLPE) and to produce an electric analog equivalent circuit. In the high-frequency range, a peak was observed, and the values of the resistance for this particular frequency were calculated for the XLPE samples with different thicknesses. Two ohmic regions with different slopes were observed, suggesting the existence of two regions in the crystalline phase with the same morphological characteristics, but different sizes (i.e., similar time constants). A reduced two-phase model was used to explain the observed behavior of samples with different thicknesses. It is suggested that thinner samples present a crystalline layer with lamellae perpendicular to the surface, whereas in thicker samples, a bulk spherulitic morphology is dominant.