A metal halide lamp includes a translucent air tight vessel having a light emitting tube portion with an internal discharge space, and sealing portions formed on both sides. A discharge medium in the discharge space contains at least metal halide and rare gas. A pair of electrodes, one ends of which are sealed at sealing portion and the other end of which are arranged in the discharge space facing each other. The discharge space has a nearly circular shape in a cross section perpendicular to the tube axis and has a structure in which the discharge medium is accumulated between the electrodes. The light emitting tube portion has a wall thickness of a lower portion thinner than that of an upper portion. The metal halide lamp has a high luminous efficiency, a quick rise of light flux and an easy manufacturing ability.