A stage apparatus includes a base, a stage movable on the base in first
and second directions, a first member movable relative to the base in the
first direction, and a second member movable relative to the base in the
second direction. The first member is placed on the second member. With
this arrangement, drive reaction-forces generated due to movement of the
stage can be canceled by moving the first and second members, resulting
in a smaller space needed for accommodating a canceling mechanism.