CLAMPING DEVICE

PURPOSE:To provide a clamping device whereby a workpiece can always be clamped in a proper attitude accordingly work with reliability can be performed by a relatively compact constitution. CONSTITUTION:In the case that supported surfaces 14a, 14b of a workpiece 14 are placed in not parallel relating to a clamp surface 3 of a clamp mechanism, clockwise moment is generated in the workpiece 14, and against this moment, counterclockwise moment is generated in each ball member 4 to rotate it. In this way, the workpiece 14 is moved so as to be placed in a more stable supported condition. When the expected supported surfaces 14a, 14b of the workpiece are brought into contact with the clamp surface 3, the ball member 4 is placed in a condition, that it is completely pressed into the inside of a base 2, and finally supported, and the workpiece 14 is surely stably supported.