A cathode ray tube capable of preventing incorrect hitting of color electron beams caused by the local doming phenomenon and the initial doming phenomenon from occurring and thus preventing displacement of colors, unevenness in colors, and deterioration of luminance from occurring is provided. The cathode ray tube includes a shadow mask made of a flat plate in which a number of apertures 2 are arranged in lines, and slits 5, 6 are formed in the line direction of the apertures 2. These slits 5, 6 have inclined faces 8, 9, 11 and 12 opposed via openings 10, 13. Due to this configuration, the displacement of apertures due to the local doming phenomenon or the initial doming phenomenon caused by the thermal expansion of the shadow mask can be suppressed. Thus, displacement of colors, unevenness in colors, and deterioration of luminance caused by incorrect hitting of electron beams can be prevented from occurring.