The development of a novel inverter power supply for a microwave oven is described. Due to its operation at a high frequency using a fast switching device, an IGBT (insulated-gate bipolar transistor), the power supply has been made light and compact. It weighs about one-fifth of the conventional ferro-resonant unit. Adopting the inverter power supply with a new control IC has made it possible to realize a new microwave oven featuring a power control function and high output power.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>