PURPOSE: To prevent early sortcircuiting and thereby offer a metallic vapor discharge lamp which assures no rise of the start voltage by restricting the distance of the connection point of the lead, led out of the light emitting tube with the current supplying electroconductive substance, from the end of the sealing part of light emitting tube, the inert gas encapsulating pressure in the outer tube, and the section area of the abovementioned electroconductive substance.

CONSTITUTION: Leads 11a, 11b in connection with main electrodes 7a, 7b are connected to supports 4a and 4b, respectively, through the nickel ribbons 13a, 13b which concern this invention. A lead 12 in connection with an auxiliary electrode 8 is connected to the support 4b. If the following conditions are all satisfied that distance of the connection point of electroconductive substance with lead l≤10mm, the encapsulating gas pressure in outer tube is no less than 100 Torr, and logS≥0.7logW-2.5, where S and W represent section area of electroconductive substance and power consumption of lamp, respectively, the change of start voltage for long-time service can be suppressed to an extent in which no practical problem will arise, i.e. below 188V.