PURPOSE: To prevent the combustion of dust explosion by the reaction of black metal film with O2 in the atmosphere, by introducing N2 contained gas and turning vacuum atmosphere back to atmospheric pressure, after evaporating the black metal film in vacuum on light reflective metal film covering fluorescent substance layer of face pannel inner face of color picture tube.

CONSTITUTION: The supply room 11 is exhausted at 10-2W1 torr. through the valve 21 by the vacuum pump 18 after the face pannel 1 is put in the room 11. Next, the pannel 1 is moved at a fixed position of the room 12 from the room 11 through the opened valve 15 after regulating vacuum degree of the black metal film evaporation room 12 at 10-1W1 torr. by the vacuum pump 19. After that, the valve 15 is shut and the pressure of the room 12 is regulated at 10-1W1 torr. of fixed vacuum degree. Next, Al is inserted in the heating apparatus 27 and is heated and evaporated and then, the black metal film is evaporated on the light reflective metal film of the pannel 1 inside. Then, the valve 7 and the leak valve 26, are shut and the pannel 1 is removed to the room 13 after the take-out room 13 is exhausted at 10-2W1 torr. by the vacuum pump 20 from the valve 23. Furthermore, the pannel is taken out from the valve 17 after introducing N2 gas in the room 13 through the valve 26 and reducing to atmospheric pressure.