A new way of drying and/or wetting a surface, such as a top surface of a substrate, is disclosed which is useful in immersion lithography. The surface is placed under a single phase extractor and a priming liquid is delivered between the single phase extractor and the surface. The single phase extractor is only activated after the priming liquid has been provided between the single phase extractor and the surface. Priming liquid is delivered to the single phase extractor during the whole of the drying and/or wetting process.