A positioning apparatus including first and second bases, and two moving
elements which are guided by the first and second bases to move on the
first and second bases. The two moving elements are supported on the
first and second bases by air bearings. A distance is ensured between the
first and second bases, and when the two moving elements move between the
first and second bases, both a guide surface of the first base and a
guide surface of the second bases are used. Also, pneumatic pressures of
the air bearings are increased to be higher than that in a case in which
the moving elements move on the first and second bases.