An electromagnetic induction heating device including an inverter which has first and second upper/lower arms (3, 4) each having two main switching elements (5a, 5b, 5c, 5d) connected in series and which converts a DC voltage to an AC voltage and supplies the AC voltage to induction coils (11, 14) for inductively heat a heating-target object, the electromagnetic induction heating device comprising: first inverter control means for operating the inverter as a half bridge type inverter by driving the switching elements (5a, 5b) of the first upper/lower arm; second inverter control means for operating the inverter as a half bridge type inverter by driving the switching elements (5c, 5d) of the second upper/lower arm; third inverter control means for operating the inverter as a full bridge type inverter by driving the switching elements (5a, 5b, 5c, 5d) of the first and second upper/lower arms (3, 4); a first resonance load circuit made up of a first induction coil and a first resonance capacitor, the first resonance load circuit being connected between output terminals of the half bridge type inverter including the first upper/lower arm; and a second resonance load circuit made up of a second induction coil and a second resonance capacitor, the second resonance load circuit being connected between output terminals of the half bridge type inverter including the second upper/lower arm; the electromagnetic induction heating device being characterized in that it further comprises: a third resonance load circuit made up of at least part of the first and second resonance load circuits (50, 70) and a third resonance capacitor, the third resonance load circuit being connected between output terminals of the full bridge type inverter including the first and second upper/lower arms; and switch means for connecting or disconnecting the third resonance load circuit to or from the inverter. first inverter control means for operating the inverter as a half bridge type inverter by driving the switching elements (5a, 5b) of the first upper/lower arm; second inverter control means for operating the inverter as a half bridge type inverter by driving the switching elements (5c, 5d) of the second upper/lower arm; third inverter control means for operating the inverter as a full bridge type inverter by driving the switching elements (5a, 5b, 5c, 5d) of the first and second upper/lower arms (3, 4); a first resonance load circuit made up of a first induction coil and a first resonance capacitor, the first resonance load circuit being connected between output terminals of the half bridge type inverter including the first upper/lower arm; and a second resonance load circuit made up of a second induction coil and a second resonance capacitor, the second resonance load circuit being connected between output terminals of the half bridge type inverter including the second upper/lower arm; the electromagnetic induction heating device being characterized in that it further comprises: a third resonance load circuit made up of at least part of the first and second resonance load circuits (50, 70) and a third resonance capacitor, the third resonance load circuit being connected between output terminals of the full bridge type inverter including the first and second upper/lower arms; and switch means for connecting or disconnecting the third resonance load circuit to or from the inverter. a third resonance load circuit made up of at least part of the first and second resonance load circuits (50, 70) and a third resonance capacitor, the third resonance load circuit being connected between output terminals of the full bridge type inverter including the first and second upper/lower arms; and switch means for connecting or disconnecting the third resonance load circuit to or from the inverter.