An air purifier comprising the following: an air-sterilizing unit and a fan device provided such that air circulates through said air-sterilizing unit. The air-sterilizing unit contains a housing and a UV-emitting element that emits deep-UV rays having wavelengths of 200 to 350 nm. The housing has a sterilization chamber, and said sterilization chamber has an air-intake opening and an air-discharge opening. The UV-emitting element is disposed in the housing so as to emit the aforementioned deep-UV rays towards the interior of the sterilization chamber. Either (A) at least part of the surface of the inside wall of the sterilization chamber comprises a UV-reflecting material that may be covered by a UV-transmitting material and/or (B) at least one reflector, at least part of the surface of which comprises a UV-reflecting material that may be covered by a UV-transmitting material, is disposed inside the sterilization chamber. After passing through the air inside the sterilization chamber, the deep-UV rays emitted by the UV-emitting element are reflected by either the inside-wall surface comprising a UV-reflecting material or the reflector surface(s) comprising a UV-reflecting material and thus pass through the air inside the sterilization chamber at least once more.La présente invention concerne un purificateur dair comprenant une unité de stérilisation dair et un dispositif de type ventilateur qui assure la circulation de lair à travers ladite unité de stérilisation dair. Lunité de stérilisation dair comporte un boîtier et un élément émettant des UV qui émet des rayons UV profonds dune longueur donde de 200 à 350 nm. Le boîtier comporte une enceinte de stérilisation et ladite enceinte de stérilisation comporte une ouverture par laquelle lair pénètre dans lenceinte et une ouverture par laquelle lair en sort. Lélément émettant des UV est disposé dans le boîtier de façon à émettre lesdits rayons UV profonds en direction de lintérieur de lenceinte de stérilisation. (A) Au
