Stage device

A stage device comprising a surface plate, two linear motors for respectively moving two moving bodies in one axis direction on said surface plate, a guide member for guiding at least one of said two moving bodies in said one axis direction, and a beam laid between said two moving bodies so as to be orthogonal to said guide member and to be moved along with said two moving bodies, said stage device characterized by comprising:

• two position sensors for respectively detecting positions of said two moving bodies,
• two origin sensors for respectively defining origin positions of said two moving bodies, and
• a controller for, responsive to detection signals from said two position sensors and said two origin sensors, controlling said two linear motors to thereby perform a position control of said two moving bodies,
• wherein said controller has a yaw axis rotation control function of individually controlling said two linear motors to thereby rotate said beam about a yaw rotation axis perpendicular to said one axis direction and, based on said yaw axis rotation control function, said controller performs, at the time of starting said stage device, a control of maintaining an orthogonality of said beam with respect to said guide member within a predetermined range even when the orthogonality of said beam with respect to said guide member changes.