METAL HALIDE LAMP AND ILLUMINATION DEVICE

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PROBLEM TO BE SOLVED : To provide a metal halide lamp of which constitution is simple while having improved light flux maintenance rate by suppressing blackening of an airtight container due to scattering of electrode materials, and to provide an illumination device which uses this. SOLUTION : This metal halide lamp is provided with a translucent and fireproof airtight container 1 with an inner volume of 0.1 cc or less; a pair of electrodes 1b which are composed mainly of tungsten and contain 0.2 to 5% of Sc oxide by the weight ratio and are sealed opposite at a distance of 5 mm or less between electrodes in the airtight container 1, at least one kind of metal halide selected from a group of Sc halide, Na, and rare earth metal; and a discharge medium which contains Xe at 5 atmospheres or higher, at 25°C and is sealed in the airtight container 1 and does not substantially contain mercury, and it is lighted under 60 w or lower of lamp electric power at stable times, and its pipe wall load is 60 W/cm2 or larger.