Patent Number: 
Section: claims

1. An exposure apparatus for exposing a substrate to an image of a pattern of an original, the apparatus comprising:a projection optical system configured to project the image onto the substrate;a stage configured to hold the substrate;a cover configured to substantially surround an exposure light path between an end portion of the projection optical system and the stage, the end portion facing the stage;a supply port provided inside the cover, via which a purge gas is supplied into a space surrounded by the cover; anda first exhaust port provided in an end portion of the cover, via which the gas is exhausted from the space, the end portion of the cover facing the stage. 2. An apparatus according to claim 1, further comprising a second exhaust port provided in the end portion of the cover and at a position outside the first exhaust port, via which the gas is exhausted from the space. 3. An apparatus according to claim 1, further comprising a third exhaust port provided in the cover, opposed to the supply port, via which the gas is exhausted from the space. 4. An apparatus according to claim 1, further comprising a vacuum pump configured to exhaust the gas via the first exhaust port. 5. A method of manufacturing a device, the method comprising:exposing a substrate to an image of a pattern of an original by use of exposure apparatus defined in claim 1;developing the exposed substrate; andprocessing the developed substrate to manufacture the device.