The complete parametric study of a small scale UV preionized TEA CO 2 laser of the CO 2/H 2 type is presented. The laser gives 10 mJ (TEM 00) and 46 mJ in multimode operation. From energy and pulse shape measurements the pulse output power of 0.2 MW (TEM 00) and 0.9 MW (multimode regime) is deduced. The spectral composition of the TEA CO 2 laser of the CO 2/H 2 type shows simultaneous multiline output in P-branch (00 01→10 00 vibrational band). All experimental measurements were conducted with a nondispersive optical cavity.