Abstract: The present invention is to provide a novel ultraviolet irradiation metal halide lamp which can produce more intense light of ultraviolet region with a wavelength near 365 [nm]. This lamp is a metal halide lamp to produce mainly light of ultraviolet region. In order to produce light with a high spectrum in ultraviolet region, particularly, light of a wavelength of 350 to 380 [nm], at least mercury (Hg) and an iron are sealed into this lamp together with a rare gas. The sealed iron into the lamp is supplied by iron iodide (FeI2) and iron bromide (FeBr2) as iron halide (FeX2) and metal iron (Fe). When a quantity of materials sealed into the lamp is expressed such that A represents a quantity of metal iron sealed into the lamp, B represents a quantity of iron iodide sealed into the lamp and C represents a quantity of iron bromide sealed into the lamp, respectively, the quantity A of the metal iron falls within the range of 0.5(B+C)?A?10.

Abstract: The present invention is to provide a novel ultraviolet irradiation metal halide lamp which can produce more intense light of ultraviolet region with a wavelength near 365 [nm]. This lamp is a metal halide lamp to produce mainly light of ultraviolet region. In order to produce light with a high spectrum in ultraviolet region, particularly, light of a wavelength of 350 to 380 [nm], at least mercury (Hg) and an iron are sealed into this lamp together with a rare gas. The sealed iron into the lamp is supplied by iron iodide (FeI2) and iron bromide (FeBr2) as iron halide (FeX2) and metal iron (Fe). When a quantity of materials sealed into the lamp is expressed such that A represents a quantity of metal iron sealed into the lamp, B represents a quantity of iron iodide sealed into the lamp and C represents a quantity of iron bromide sealed into the lamp, respectively, the quantity A of the metal iron falls within the range of 0.5(B+C)?A?10.