1. A jig of a heating apparatus, the jig being configured to support a ring-shaped workpiece when conveying and heating the workpiece, the jig comprising:a central structure unit;
a rotary drive mechanism accommodated in the central structure unit; and
a workpiece support connected to the central structure unit and configured such that the workpiece is placed on the workpiece support to surround the central structure unit,
wherein the workpiece support comprises a plurality of rotating rollers arranged in a circumferential direction around the central structure unit,
wherein the central structure unit comprises:
a conveyor connecting portion configured to suspend the workpiece support together with the workpiece placed on the workpiece support; and
a driver connecting portion from which a driving force is input to the rotary drive mechanism, and
wherein the rotary drive mechanism is configured to rotate the rotating rollers by the driving force to rotate the workpiece along a ring shape of the workpiece.