The charge relaxation processes in the films based on R-BAPB polyimide with different degree of crystallinity have been studied. The supramolecular structure effect on the charge relaxation processes in the films under elevated humidity conditions was revealed. The obtained experimental data was analyzed in the context of the present-day knowledge of the charge relaxation mechanism. The complex spectra of the thermally stimulated depolarization currents (TSDC) were resolved into individual components and described by the first-order kinetics equations using computer simulation. The TSDC activation energies were calculated and interpreted in terms of the mechanism of release of charge carriers. It was shown that the increment of crystallinity degree of the polyimide films lead to a decrease in the electret state stability at elevated temperature and high humidity.