To provide a workpiece holder capable of preventing the torque from being applied to a bearing pin.

The workpiece holder has a turning bridge 10 supported between two bearing walls 13 and 14. The bearing walls 13 and 14 demarcate a working area from the side surface. At least one drive motor 23 turns the turning bridge 10, and the motor 23 is disposed on at least one of outer surfaces of the bearing walls 13 and 14 outside the working area. The turning bridge 10 has a gear ring 21 adjacent to either or each of the bearing walls 13 and 14, and the gear ring 21 is connected so as to transmit the power to a drive gear wheel 27 driven by at least one drive motor 23. Thus, bearing pins 11 and 12 of the turning bridge 10 need not transmit the drive torque, or any torque is not applied thereto, enabling correct traveling and correct positioning.