The results of experimental investigations on the tool-electrode erosion made of materials such as: copper, steel and W + 10% Re depending on the energy regimes by applying pulsed electric discharge machining (PEDM) are presented in this paper. The electrodes applied to the surface machining process were made of conductive materials in the form of bars of different sizes and subjected to investigations at atmospheric conditions at normal pressure under different energy processing regimes. We studied the effects that occur between base electrodes (anode and cathode) varying polarity and charge voltage of the condenser battery, while the other regimes remained constant (the gap, the frequency of electrical discharges, the capacity and the processing duration). The results demonstrate that the electro-erosion resistance of the toolselectrodes depends at the same time on the physico-mechanical properties of their materials, their geometric shape and the power of the energy released in the gap at a solitary discharge.