PURPOSE: To use an optical system with a narrow focus margin and to improve the accuracy of pattern transfer to a current wafer surface by detecting the inclination of an exposed area on the wafer surface and slanting a stage or reticle.

CONSTITUTION: A normal positioning mechanism moves a wafer 6 to a specific position and then a inclination detection part 8 detects the inclination of the wafer surface of the exposed area. Then at least either of the reticle 4 and wafer stage is slanted so as to correct the detected inclination. Consequently, the inclination of the exposed area of the wafer surface is corrected before the exposed area is exposed to perform accurate pattern transfer to the wafer surface in the corrected state.