Exposure apparatus

An exposure apparatus comprising:

• an exposure unit for illuminating a mask pattern to transfer an image of the mask pattern onto a photosensitive substrate;
• a chamber which houses the exposure unit, and in which an atmosphere is kept in a predetermined condition;
• an air-conditioner for adjusting the atmosphere in the chamber to the predetermined condition;
• a drain for draining condensate produced in the air-conditioner;
• and
• a filter interposed between the air-conditioner and the drain for removing impurities in the condensate produced in the air-conditioner.

An exposure apparatus comprising:

• an exposure unit for illuminating a mask pattern to transfer an image of the mask pattern onto a photosensitive substrate;
• a chamber which houses the exposure unit, and in which an atmosphere is kept in a constant condition;
• an air-conditioner for adjusting the atmosphere in the chamber to the constant condition;
• a trapping system for temporarily trapping condensate produced in the air-conditioner;
• a detector for detecting the amount of the liquid in the trapping system;
• a drain path for draining the condensate in the trapping system to the outside of the exposure apparatus;
• an opening/closing mechanism provided in the drain path for opening and closing the drain path;
• and
• a controller for controlling the opening/closing mechanism according to the amount of the liquid in the trapping system detected by the detector.

An exposure apparatus comprising:

• an exposure unit for illuminating a mask pattern to transfer an image of the mask pattern onto a photosensitive substrate;
• a chamber which houses the exposure unit, and in which an atmosphere is kept in a constant condition;
• an air-conditioner for adjusting the atmosphere in the chamber to the constant condition;
• a trapping system for temporarily trapping condensate produced in the air-conditioner;
• a drain path for draining the condensate in the trapping system to the outside of the exposure apparatus;
• and
• a mechanism provided in the drain path for preventing a pollutant from entering the air-conditioner from the outside of the exposure apparatus through the drain path.