A metal halide lamp according to the present invention includes: a main tube (6) made of a light-transmitting ceramic and forming a part of an arc tube; a first thin tube (7a) coupled to a first end of the main tube (6); a second thin tube (7b) coupled to a second end of the main tube (6); a pair of electrodes (5a, 5b), which are inserted into the first and second thin tubes (7a, 7b), respectively, such that the far ends thereof face each other inside the main tube (1); and a first metal halide enclosed in the arc tube. A second metal halide, which has a lower vapor pressure than that of the first metal halide, is further enclosed in the arc tube. And the main tube (6) has portions, of which the inside diameter decreases monotonically toward the ends.