A lithographic apparatus is provided. The apparatus includes an illumination system for conditioning a beam of radiation, and a support for supporting a patterning device. The patterning device serves to impart the beam of radiation with a pattern in its cross-section. The apparatus also includes a substrate table for holding a substrate, a projection system for projecting the patterned beam onto a target portion of the substrate, and a high voltage conductor in a part of the apparatus that is evacuated or at a low pressure during normal use of the apparatus. The conductor is coated by an isolation layer having a conductivity that is high enough to prevent charge build-up on the outside thereof during use of the apparatus, and low enough to limit peak current flow during a breakdown.