A scanning exposure apparatus measures levels of a substrate at a predetermined position on the substrate at a first measurement point during the acceleration period and a second measurement point during the constant velocity period, obtains a correction value for a measurement error due to factors associated with acceleration based on the measurement results, corrects the measured level using the obtained correction value and exposes the substrate so that the level at a given position on the substrate becomes equal to the corrected level, when the substrate is exposed at the given position after the level is measured while the stage accelerates, and exposes the substrate so that the level at a given position on the substrate becomes equal to the measured level measured, when the substrate is exposed after the level of the substrate at the given position is measured while the stage moves at a constant velocity.