METAL HALIDE LAMP AND ULTRAVIOLET IRRADIATION DEVICE

To secure required illuminance characteristics while suppressing the deterioration of a metal halide lamp.SOLUTION: A metal halide lamp 10 includes an arc tube 11, a sealing part 12, a mouthpiece member 13, an electrode 14, a metal foil 15, an internal lead 16 and an external lead 17. The arc tube 11 is made of quartz glass transmitting ultraviolet rays, formed in a tubular shape, and sealed by the sealing part 12 provided on both ends in a tube axial direction, and has a space 11a at the inside thereof. Thallium iodide (TlI), iron and mercury are enclosed in the space 11a, the enclosed amount of the thallium with respect to the iron being 0.2 or more and 0.3 or less in mass ratio.SELECTED DRAWING: Figure 1 【課題】メタルハライドランプの劣化を抑制しつつ必要とする照度特性を確保する。【解決手段】メタルハライドランプ１０は、発光管１１と、封止部１２と、口金部材１３と、電極１４と、金属箔１５と、内部リード１６と、外部リード１７とを備え、発光管１１は、紫外線を透過する石英ガラス製で、管状に形成され、管軸方向の両端に設けられた封止部１２で封止され、内部に空間１１ａを有し、空間１１ａには、ヨウ化タリウム（ＴｌＩ）と鉄と水銀とが封入され、鉄に対するタリウムの封入量は、質量比で０．２以上０．３以下である。【選択図】図１