This work represents the development of a two-arm CO2 laser, which proved that discharge can be sustained using single power supply. This development constitutes the redesign and implementation of a new resonator arrangement. The redesign analysis is based upon two methods of calculation. The First methods represent the discharge breakdown in CO2-N2-He gas mixer, and based on experimental results from literature and engineering relationships. The parameters calculated are circuit current, input power, tube and resonator length and output power. The second method represents the steady state discharge in CO2 laser and is upon based on physical relations, experimental results, calculated number of molecules, electric field, tube length, resonator length, stability, and output power. The two methods have been combined in one computer program written in Matlab software. All above analyses are based upon that the power supply would achieve a maximum voltage of 30 kV and maximum current of 100 mA. The laser resonator consisted of two electric discharge Pyrex tubes, each of 750 mm length, 16mm inner diameter and tube thickness of 2mm. Two negative electric discharge electrodes (cathodes) are made of aluminum and two positive electrical discharge electrodes (anode) are made of stainless steel pins held in Teflon mounting.