A pulsed transversely excited gas laser device includes a pair of main electrodes having main surfaces opposing each other across a main discharge gap and extending along the optical axis of the laser. A corona discharge preionizer for radiating ultraviolet radiation is substantially accommodated within a recess formed on the main surface of one of the main electrodes at an upstream side of the foot of the main discharge 3. The corona discharge preionizer is separated from the inner wall and bottom surface of the recess except at a surface portion thereof which is in contact with a projection extending sideways from a side wall of the recess next to the main discharge. The corona discharge generated over the preionizer radiates ultraviolet radiation to preionize the laser gas.