An electron gun fixer comprising bulb spacers fixed to an electron gun to be inserted into a bulb neck. Each of the bulb spacers has a supporting portion to be put into press contact with the inner surface of the bulb neck. The expression “R1≧R2>R3” holds for the supporting portion, where R1 is the radius of curvature in the cross section along the direction of insertion of the electron gun into the bulb neck, R2 is the curvature of a peripheral part in the cross section perpendicular to the direction of insertion, and R3 is the radius of curvature for the remaining parts in the cross section perpendicular to the direction of insertion. R2 is substantially equal to the radius of curvature R0 of the bulb neck.