Positional information of a movement plane of a
wafer stage is measured using an
encoder system such as, for example, an X head and a Y head, and the
wafer stage is controlled based on the measurement results. At the same time, positional information of the
wafer stage is measured using an interferometer
system such as, for example, an X interferometer and a Y interferometer. When
abnormality of the
encoder system is detected or when the wafer stage moves off from a measurement area of the
encoder system, drive control is switched to a drive control based on the measurement results of the interferometer system. Accordingly, drive control of the wafer stage can be performed continuously in the entire
stroke area, even at the time when
abnormality occurs in the encoder system.