A planar repetitively pulsed microwave-pumped CO2 laser with discharge channel lengths of 250 and 470 mm is experimentally investigated. An average laser power of 60 W at a wavelength of 10.6 μm is attained. A peak power of 1300 W is reached in the repetitively pulsed regime. The dependences of the shape and energy of CO2 laser pulse on the introduced power, working gas mixture composition and pressure, and pump-pulse repetition rate and width are analysed.