To provide a workpiece chucking device which facilitates change of a mounting location of a chucking mechanism.

According to the structure of the chucking device, while the chucking mechanism 18 is detached from a frame 8 and then held by a chucking detaching/attaching device 41, the frame 8 is rotated together with a support plate 5. Therefore positioning recesses 11b, 12b formed in the frame 8 at different locations are disposed at locations opposed to the chucking mechanism 18 held by the chucking detaching/attaching device 41.