Lithographic apparatus immersion damage control

A lithographic apparatus includes a substrate table to hold a substrate; a substrate table position measurement system to measure a position quantity of the substrate table, a projection system to project a patterned radiation beam onto a target portion of the substrate, a fluid supply system to supply an immersion fluid in a space between a downstream lens of the projection system and the substrate, and a fluid supply system position measurement system to measure a position quantity of the fluid supply system. To prevent a collision between the fluid supply system and the substrate table, a damage control system of the lithographic apparatus may include a calculator to calculate a dimensional quantity of a gap between the fluid supply system and the substrate table from the positioned quantity of the substrate table and the position quantity of the fluid supply system. The damage control system may generate a warning signal when the dimensional quantity goes beyond a predetermined safety level.