The parameters of a periodic-pulse planar CO2-laser pumped by microwave (MW) discharge at a frequency of 2.45 GHz have been studied experimentally. The laser comes in two versions with longitudinal discharge- gap lengths of 250 (version A) and 470 (version B) mm. An average output power of 60 W could be achieved at a wavelength of 10.6 μm. The peak output power in the periodic-pulse mode of operation is about 1300 W. The shape and energy of the laser pulse have been investigated as a function of nput power, working mixture composition, pressure, repetition frequency and duration of microwave pumping pulses.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.