A dielectric heating system which is provided with a high frequency oscillator, a housing which forms part of a waveguide and is provided with a loading opening and unloading opening, first and second conductive closing members which respectively close the loading opening and the unloading opening from the inner side of the housing, and a first position holding member which holds the object to be heated inside the housing, which makes the first conductive closing member slide to open the loading opening and charges the object to be heated into the housing, and which makes the second conductive closing member slide to open the unloading opening and unload the object to outside the housing.