Abstract: In a switching device of an induction heating cooker, an oppositely poled diode for conducting a reverse current is coupled across the collector-emitter portion of a switching element provided in the first switching device, and turn-ON operation of the switching devices does not OCCUR in normal operation of the DUTY FACTOR T.sub.2 /T.sub.1 .apprxeq.0.5.

Abstract: An induction heating cooker has a rectifier (13) for producing pulsating DC current, an inverter (14) which receives the pulsating current given from the rectifier (13) and produces a high frequency output current and a load circuit (15) including an output coil (21) and a resonance capacitor (22) connected in series to each other to receive high frequency output signal from the inverter, and the variation or adjustment of output electromagnetic power is made by changing duty ratio of the high frequency output current of the inverter by giving variable duty ratio setting signals to switching elements (Qa, Qb) in the inverter 14; the frequency of the high frequency output current of the inverter 14 is fixed, and therefore, unpleasant interference sound is not generated at parallel simultaneous operation.