Abstract: The invention relates to improved gas lasers with an increased power output compared with conventional lasers of a similar size. There is established an axial magnetic field and an electric field either parallel therewith or perpendicular thereto, the interaction of such fields resulting in a substantially increased convective instability of the gas discharge, resulting in an increased heat transfer to the walls of the laser. The laser discharge is in the axial direction parallel with the magnetic field. The components of the laser, except for the means of establishing such magnetic and electric fields of predetermined strength, are of a conventional nature. The invention further relates to a method of operating a gas discharge laser in such a manner that there is established an axial magnetic field and an electric one either orthogonal or parallel therewith, resulting in a strong convection, heat transfer to the walls and dramatically increased power output.