An apparatus for transferring a target, such as a substrate or a substrate support structure onto which a substrate has been clamped, from a substrate transfer system to a vacuum chamber of a lithography system. The apparatus comprises a load lock chamber for transferring the target into and out of the vacuum chamber. The load lock chamber comprises a first wall with a first passage providing access between a robot space and the interior of the load lock chamber, a second wall with a second passage providing access between the interior of the load lock chamber and the vacuum chamber, and plurality of handling robots for transferring the targets comprising: a first handling robot movable within the robot space to access the substrate transfer system and the first passage; and a second handling robot movable within the load lock chamber to access the first passage and the second passage.