The design of an electron gun was examined from the viewpoints of pre-focus lens, main lens, corner focus and cathode current. Accordingly, multi-beam electron gun has been developed to catch up with the remarkable progress of resolution in computer peripheral devices such as digital still cameras and video boards. Multi-beam electron gun has two slot beam apertures of G1 for one cathode, and a key point of its design is to realize two-beam simultaneous convergence and focusing. To satisfy this condition, the divergence angles of electron beam bundles were designed. With this multi-beam electron gun that is superior in both of beam spot size and drive voltage, the 5 million pixels CRT could be realized.