Metal Halide Lamp

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A metal halide lamp has an arc tube (3) including an arc tube container as an envelope made of an oxide-based translucent ceramic material such as alumina, and the arc tube is filled with cerium halide as a luminescent material (17) and a halide of a rare earth element that is more reactive with the ceramic material than is the cerium halide. Accordingly, a reaction between the oxide-based translucent ceramic material and the halide of a rare earth element is accelerated while a reaction between the oxide-based translucent ceramic material and the cerium halide is suppressed. This suppresses a decrease of the cerium halide that serves for light emission, and also reduces changes in the lamp color temperature. Thereby, lowering of flux maintenance factor and color temperature in aging of the lamp are suppressed, and the thus provided metal halide lamp with an alumina ceramic tube for indoor and outdoor use has a white light source color and it has a high-wattage, high luminous efficiency, and a long service life.