A cathode ray tube comprises a panel having a fluorescent screen on an inner surface; a funnel connected to the panel, an electron gun housed in the funnel; emitting electron beams; and a shadow mask for selecting colors of the electron beams emitted from the electron gun, wherein the deflection yoke comprises a deflection coil for deflecting the electron beams in horizontal and vertical directions, a holder for insulating the deflection coil, and a ferrite core for reducing a magnetic field generated by the deflection coil, and an opening is formed on a flange portion of an opening section on a screen side of the deflection coil.