To provide a facility for decontaminating organic halogen contaminants, which can reduce the maintenance frequency, and to provide a method for decontaminating organic halogen contaminants, which can inhibit the reduction of treatment efficiency.

The facility for decontaminating organic halogen contaminants and the like provided herein has workspace for exposure to gases containing organic halogen compounds and a light source for illuminating the workspace, by which objects contaminated with organic halogen compounds are decontaminated in the workspace. The facility for decontaminating organic halogen contaminants is characterized in that a mechanism for removing ultraviolet rays is further arranged therein so as to illuminate the workspace with light from which 90% or more of the light with wavelengths of 380 nm or less is removed from the light radiated from the light source.