Abstract: A dielectric heating device for heating a dielectric sandwiched between a pair of electrodes is disclosed in which an oscillation circuit is made up of the above-mentioned electrodes, a coil connected in series with the electrodes, a first capacitor connected in parallel with a series circuit made up of the electrodes and the coil, another series circuit connected in parallel with the first capacitor and made up of second and third capacitors and a field effect transistor having source and drain electrodes connected respectively to one and the other electrodes of the second capacitor and a gate electrode connected to a junction point for connecting the first and third capacitors.