A cathode ray tube has a panel portion 1 with a phosphor layer 5 formed on its inner face, a neck portion 2 accommodating an electron gun 9, a funnel portion 2 for coupling the panel portion 1 to the neck portion 2 and a color selective electrode assembly 6 having a number of electron beam passing openings arranged opposite to the phosphor layer 5 with a space therebetween. The color selective electrode assembly is installed within the panel portion 1. An electron beam reflection film of a bismuth oxide thin film 6R having a bulk density of at least from 41 g/cm3, to 9.3 g/cm3, e.g., is formed on the face of the color selective electrode assembly 6 against which the electron beams 14 emitted from the electron gun 9 collide. The cathode ray tube is capable of displaying high density and high resolution image.