An apparatus includes a static gas bearing provided upon a first object and configured to form a gas layer between the first object and a second object by use of gas supplied thereto, and to support the first object movably relative to the second object, a plurality of exhaust grooves provided upon the first object and configured to surround the static gas bearing, and a plurality of exhaust flowpassages provided through the first object, connecting to a respective one of the plurality of exhaust grooves, and configured to exhaust gas from a respective one of the plurality of exhaust grooves. An outermost exhaust flowpassage of the plurality of exhaust flowpassages connected to an outermost exhaust groove, which is outermost of one of the plurality of exhaust grooves with respect to the static gas bearing, is shorter than an innermost exhaust flowpassage of the plurality of exhaust flowpassages connected to an innermost exhaust groove, which is innermost one of the plurality of exhaust grooves with respect to the static gas bearing, so that a conductance of the outermost exhaust flowpassage is greater than that of the innermost exhaust flowpassage.