Abstract: A turntable includes a driving source, a workpiece holder holding a workpiece to be processed by a tool, a motive power transmission mechanism that can transmit the motive power from said driving source to said workpiece holder, and a load mechanism that can activate said motive power transmission mechanism under a load-applied state, and applying a predetermined load to said motive power transmission mechanism during processing of said workpiece.

Abstract: To provide a balancer mechanism where a balancing rotary moment, which offsets at least a part of a rotary moment operating on a rotary shaft, operates on the rotary shaft by a gas spring to reduce the rotary moment simply and reliably. The balancer mechanism for rotary shaft (8) is provided with a cam member (10) fixed to the left end of rotary shaft (3), a cam follow-up member (15) which makes contact with the cam member (10) to follow it up, and a gas spring (20) comprising a gas spring (20) elastically energizing the cam follow-up member (15) toward the cam member (10) and operates a balancing rotary moment offsetting at least a part of the rotary moment of rotary shaft on the rotary shaft (3) via the cam follow-up member (16) and the cam member (10).