US Patent 7342237 Lithographic apparatus and device manufacturing method

A lithographic apparatus comprising: an illumination system for providing a projection beam of radiation; a gas pressure controlled article clamp for clamping an article to be placed in a beam path of the projection beam of radiation; and a pressure circuit for controlling the article clamp, comprising a supply line for connection with the article clamp. According to the invention, a buffer volume is provided for providing a buffered gas pressure pulse in the supply line. In this way, faster clamp response times can be realized.