In this work, it is shown that the effect of a corona discharge and a dielectric barrier discharge differs in depth of charge penetration and relaxation time. The relaxation time and the mechanism of charge relaxation in polylactide films were determined using thermally stimulated depolarization current (TSDC).Experimental data are analyzed based on modern ideas about the mechanism of charge relaxation. The activation energies are calculated based on a model that considers the intrinsic conductivity of the dielectric. By the method of computer modeling, the complex TSDC spectra are decomposed into separate elementary maxima, which are described by first-order kinetics, and the activation energies corresponding to them are determined.