An exposure apparatus for exposing a substrate with an exposure light beam passing through a mask comprises a movable stage for moving the substrate, a stage chamber for accommodating the movable stage, a transport system for transporting the substrate into the stage chamber, and a first alignment system for performing positional adjustment for the substrate with respect to the movable stage in the stage chamber. The position of an exposure objective delivered from the transport system into the stage chamber can be subjected to positional adjustment by using the first alignment system. The stage chamber and the movable stage can be assembled to a frame of the exposure apparatus in accordance with the module system. The exposure apparatus includes a second alignment system for performing positional adjustment for the substrate installed on the movable stage at an exposure position.