An electrode is fixed hermetically to one end of a conductive tube with a titanium solder and the other end of the conductive tube is closed. Thus, the conductive tube has an airtight structure and an argon gas is sealed therein. This conductive tube is fixed hermetically to a transparent alumina tube using a sealer. Further, sodium amalgam is provided at an inner end of the transparent alumina tube. The conductive tube is prevented from being deformed and sodium of a luminescent material is positioned inside the discharge tube, thus providing a high-pressure sodium lamp in which a lighting color and lamp voltage are prevented from varying during the lamp lifetime, the time required for reaching a stable lighting state after turning on the lamp is short, and the variation in lamp voltage is suppressed.