Disclosed is an electrostatic charging apparatus for electrostatically charging the inside surface of the screen panel of a color cathode ray tube to make powdery phosphor to be applied to the inside surface by the electrical attraction, which comprises a corona charger for electrostatically charging the inside surface, a stand frame for supporting the corona charger, a mounting means for supporting the screen panel with the part of the inside surface of the display being wholly exposed to the corona charger with a space therebetween, and a power supply for supplying a high voltage to the corona charger, wherein the corona charger has a convex surface with a plurality of charging electrodes uniformly distributed.