Internal charge distribution in carnauba wax thermoelectrets was measured. It was found that substantial volume charges exist within the electrets. These charges form a characteristic permanent volume charge distribution which is essentially the same for all investigated (over 100) electrets regardless of the magnitude of the electric field used for polarizing the electrets, duration of polarization, electret age, surface charge, or storage conditions. The existence of this characteristic volume charge distribution indicates that the primary mechanism responsible for the electret effect in the carnauba wax thermoelectrets is a trapping of electric charges within the electret material rather than a permanent microscopic polarization of the material.