Lithographic projection assembly, including at least one load lock for transferring objects, in particular substrates, between a first environment and a second environment, the second environment preferably having a lower pressure than the first environment; an object handler including a handler chamber in which the second environment prevails; and a lithographic projection apparatus including a projection chamber. The handler chamber and projection chamber can communicate for transferring the objects. The load lock includes a load lock chamber; evacuation device for evacuating the load lock chamber; and door device for closing the load lock chamber during evacuation and for opening the load lock chamber to enter an object in or remove an object from the load lock chamber. The load lock chamber may be provided with at least two mutually distinct object support positions.