Using insulated gate bipolar transistors (IGBT), we constructed an efficient, all solid state exciter for high efficiency, high power operation of a transversely excited atmospheric (TEA) CO2 laser. The exciter was composed of a high-voltage pulse generator and a two-stage magnetic pulse compressor. Forty-eight series and two parallel IGBTs were used as the main switch of the pulse generator. The maximum switching voltage as high as 36 kV was achieved with a transfer energy of about 100J. The pulse generator, employing an LC inversion circuit, produced a 65 kV, 7.5μs pulse, which was compressed to 0.5μs by the pulse compressor. The use of an IGBT stack decreased energy waste in a snubber circuit, resulting in a high efficiency of more than 90%. By applying the exciter to a TEA CO2 laser with a discharge volume of 0.5l, an average laser power of 4.6 kW was attained at a repetition rate of 550 pps for a switching energy of 78J. The overall efficiency of the laser was as high as 10.5%. A repetition rate of 1.1 kpps was attained, resulting in an average laser power of 3.4 kW by reducing the switching energy to 42J.