A new type of tube-plate electrodes more suitable for low order transverse electric (TE) modes output in fields like laser welding has been developed. It has a bigger size in the direction of the laser beam, so that more uniform discharge and longer discharge length can be obtained. Its width in the direction of gas flow is determined by the output laser mode, so that the active volume can be fully used. Its stable and even discharge makes the ballast resistor smaller which reduces extra power consumption. Compared with the former electrodes, it has greatly increased the input power density, the maximum output power and efficiency of mode-selecting lasers. As a result, high electro-optic conversion efficiency of 20% for multimode output, 15% and laser total efficiency of 8% for low order TEM11 output are obtained. It is suitable for home made transversal CO2 lasers, making them capable of acquiring high efficiency for different TE modes output and more suitable for low order TE modes output in fields like laser welding.