A metal halide lamp of the present invention comprises a luminous tube alone without any outer bulb, the luminous tube containing metal halides such as neodymium halides (NdX3), dysprosium halides (DyX3) and cesium halides (CsX) in a total amount by mole of 1 x 10-6 to 8 x 10-6 mol/cc and the following molar ratios: (see fig.I) (see fig.II) as well as rare gas serving as starting auxiliary gas and mercury serving as buffer gas. This structure permits a predetermined vapor pressure of the metal halides sealed in the luminous tube to be obtained without increasing the wall load, as well as the formation of a metal halide lamp having a long life and good color characteristics.
