PURPOSE: To keep heat transfer efficiency and obtain high luminance in a simple construction than that using refrigerant by installing a side wall peripheral metal body which contacts in a side wall periphery of a phosphor screen panel through a grease-like heat radiation material, and a heat radiation fin thereon.

CONSTITUTION: A glass plate 12, which is arranged through colorless, transparent silicon resin to prevent spreading out of a grease-like heat radiation material to an image surface, is installed on the outer surface of an image surface of a phosphor screen panel 11 of a cathode-ray tube 10 to increase heat transfer. A cooling metal plate 14 having a heat radiation fin 14a which is installed through the greasep-like heat radiation material which is placed between periphery of the image surface of the panel 11 is arranged. A supporting plate 15 which is arranged to increase heat transfer through the grease-like heat radiation material in the side periphery, the metal plate 14, and a heat radiation sheet 16 for improving contact of the supporting plate 15 with a panel side wall are installed. This design is effective for heat transfer, and high luminance is obtained by simple construction.