Abstract: A high electrical power is input in a gas-swept electrical discharge for gas laser by controlling with a high electrical efficiency and without dissipative resistance. A discharge chamber is swept through with a gas at a high velocity wherein transverse to the flow direction, the gas discharge burns as a steady-field discharge between an anode and several cathodes opposite the anode. These are disposed in tandem in the flow direction. Power is supplied to each individual cathode by means of a fast, independently controlled switched-mode power supply unit constant current characteristics wherein the current is supplied to the switched-mode power supply unit by series-connected partial voltage sources of the cathodes. A pre-ionization device is provided on the flow bounding surface of the discharge chamber.