PURPOSE: To economically provide a lamp of good quality, by loading the lamp, in the process of filling the lamp with mercury, with a capsule having a predetermined amount of mercury sealed therein, and breakig the capsule by a laser beam after the lamp is evacuated to release the mercury from the capsule to the space inside the lamp.

CONSTITUTION: The capsule 14 with mercury sealed therein is loaded in a recess 17 provided at a pant of the spacer 4. The mercury containing capsule 14 may readily be fixed to the part with an inorganic adhesive agent 8, for example. After the evacuartion process of the lamp is finished (after the tip-off), a laser beam 18 from a laser oscillator is focused on the mercury containing capsule 14 to melt down the capsule 14 to release the mercury into the space inside the lamp. Since the outer bulb 1 is transparent, the laser beam 18 from outside can readily be focused through the outer bulb 1 on the mercury containing capsule 14.