PURPOSE: To keep off the unsteadiness of deflection in a flat type cathode-ray tube that makes a deflecting signal voltage so as to be overlapped by means of capacitive coupling, by installing an electron beam regulating member between an electrostatic deflecting plate and an electrode at the final stage of an electron gun.

CONSTITUTION: A beam regulating member 14 shielding a deflecting plate 9a from the impact of an electron beam is installed between a couple of electrostatic deflecting plates 9a, 9b and an electrode fourth grid G4 at the final stage of an electron gun 4. This beam regulating member 14 is given the same voltage as the side of a deflecting plate 9b given a fixed voltage, for example, the identical voltage VRH as an opposite electrode 3. If positional adjustment for a beam's range by a centering magnet takes place, such a matter that a beam current flows into the deflecting plate 9a can be effectively avoided, and in combination with the fact that centering adjustment can be fully achieved, a beam's landing signal on top of a phosphor screen 3 can be steadily set in a highly accurate manner.