A cathode ray tube device capable of providing sufficient shielding effect against leaking alternating electric field while exhibiting high reliability during long use. Alternating electric field generated by a deflection yoke is sufficiently reduced by the shielding effect produced by a conductive film formed on a funnel portion. A gap formed between the conductive film and an insulating sheet provided between the conductive film and the deflection yoke, due to dimensional error, is filled with insulating silicone grease, so as to avoid secular degradation of insulation which otherwise may occur due to accumulation of dust and other matters.