The present invention relates to a sealing apparatus of discharge lamps, and more particularly, to a sealing apparatus adapted to be applied at a sealing structure of an enclosure, such as a plasma display and a gas-filling bottle, for permanently sealing the same, which is substantially a multiunit tube, primarily comprising at least an evacuated metal tube and an evacuated alloy tube coupled to the evacuated metal tube by an airtight manner, being adapted to interface with an end of a tube connecting to a glass substrate of an enclosure, such as a plasma display or a discharge lamp.