X-Y stage apparatus capable of reducing the number of drive sources

An X-Y stage apparatus, comprising:

• a base;
• a guide rail fixed on the base and extending in a first predetermined direction;
• a first slider movable in the first direction along the guide rail, the first slider comprising a beam, a T-shaped section, and an arm member, the beam being in parallel with the upper surface of the base and extending in a second direction orthogonal to the first direction, the T-shaped section being movable along the guide rail at an end of the beam, and the arm member extending in the first direction at the other end of the beam;
• and
• a second slider movable in the second direction along the beam,
• wherein the first slider is supported movably on the base by a plurality of first static pressure air bearing units disposed at two positions on the lower surface of the T-shaped section, at at least one position on the lower surface of the beam at the central portion thereof and at the two positions on the lower surface of the arm member;
• and
• the second slider is supported movably on the base by a plurality of second static pressure air bearing units disposed on the lower surface of the second slider at a plurality of positions thereof.