Exposure apparatus and exposure method

An exposure apparatus which transfers a pattern of a reticle onto a substrate using EUV (Extreme Ultraviolet) light, the apparatus comprising:

• a beam providing unit including at least a first structure, a second structure and a reticle stage configured to hold and to move the reticle, said beam providing unit being configured to provide EUV light beam having pattern information to the substrate, said first structure and second structure being supported independently of each other, said second structure including an illumination optical system, and said first structure including a barrel containing a mirror which reflects EUV light provided by said illumination optical system so as to illuminate the reticle and a projection optical system which projects EUV light beam reflected from the reticle onto the substrate, said illumination optical system being configured to emit the EUV light beam such that the reticle is illuminated by said illumination optical system via said mirror contained in said barrel;
• a measurement unit which measures a relative variation between said first structure and said second structure;
• a driving mechanism which drives said second structure;
• and
• a controller which controls said driving mechanism on the basis of a measurement result obtained by said measurement unit so as to reduce a relative variation between said first structure and said second structure in at least a period during which the pattern is transferred onto the substrate.