To provide a cathode-ray tube device having a cooling mechanism in which a cooling liquid, a mixed liquid of ethylene glycol and glycerin to be colored by a dye, capable improving chromaticity and contrast is sealed.

This device is used in a projector device for projecting an image on a screen. A cathode-ray tube body 2 has, on the front thereof, a face panel 8 on which a color component image is displayed. A cooling mechanism 3 is attached to the front of the cathode-ray tube body 2 and cools down the face panel 8. A cooling liquid 11 is sealed in a liquid vessel 10 of the cooling mechanism 3. A front panel 4 is attached to the front of the cooling mechanism 3. The cooling liquid 11 is prepared by mixing such that ethylene glycol with glycerin, followed by dissolving of a little quantity of an aqueous solution of a dye. The cooling liquid 11 contains 0.5 to 20 pts.vol. of water per 100 pts.vol. of the total quantity of ethylene glycol and glycerin.