Patent ID: 8767182

Claim:
A movable body drive method in which a movable body is driven substantially along a two-dimensional plane, the method comprising: a first process in which positional information of the movable body in directions of three degrees of freedom within a plane parallel to the two-dimensional plane is detected, using a first detection device which detects positional information in directions of three degrees of freedom within the plane parallel to the two-dimensional plane from measurement results using a measurement beam irradiated along the two-dimensional plane between the outside of the operating area of the movable body and the movable body, and positional information of the movable body in a direction perpendicular to the two-dimensional plane and a tilt direction with respect to the two-dimensional plane is also detected, using a second detection device which detects positional information of the movable body in a direction perpendicular to the two-dimensional plane and a tilt direction with respect to the two-dimensional plane from measurement results using a measurement beam irradiated along the two-dimensional plane between the outside of the operating area of the movable body and the movable body; and a second process in which on switching from servo control of the position in the directions of three degrees of freedom of the movable body using the first detection device to servo control of the position in the directions of three degrees of freedom of the movable body using an encoder system, a detection device that detects positional information of the movable body in the direction perpendicular to the two-dimensional plane and the tilt direction around at least one axis with respect to the two-dimensional plane is switched from the second detection device when the movable body is in a suspended state, to a third detection device that has a plurality of detection positions placed in at least a part of an operating area of the movable body, and detects positional information of the movable body in the direction perpendicular to the two-dimensional plane using detection information detected when the movable body is positioned at any one of the detection positions.