Abstract: An electromagnetic field shielding circuit is disclosed. The circuit comprises a phrase inverting circuit, coupled to a turn in the secondary windings, for generating an inverted phase with respect to a phase of a voltage signal induced to the anode electrode from the secondary windings. An oscillation circuit oscillates a voltage signal output from an output node of the phase inverting circuit. The oscillating circuit matches an oscillating signal with a high voltage level signal. An electromagnetic field generation circuit applies a voltage signal output from an output mode of the oscillation circuit. This generates an electromagnetic field responsive to the voltage signal substantially around the circumferential periphery of the front portion of the picture tube. This electromagentic field cancels and shields the electromagnetic field generated from the anode.