PURPOSE: To correct quench deformation at the same time as tempering without premeasuring, with respect to a quenched part, esp. a rotary body, by providing a rotating roller, a supporting roller, a load-applying roller and a heater around a workpiece to be corrected.

CONSTITUTION: While putting a load-applying roller 3 to the right by a load- applying means 10, a ring 1 as matter to be reformed is concentrically placed on a rotary disc 9 in the resulting empty space, and the roller 3 is brought into contact with the ring 1 by the means 10. After a necessary load is applied to the roller 3, a driving roller 2 is rotated by a motor 13 to start the rotation of the ring 1 existent in contact with said roller 2. Then, the ring 1 is heated at a tempering temp. by heaters 5, 6 and rotated for a few minutes undr this atmospheric condition. Thereafter, a heating power source is turned OFF, said part 1 is cooled, and then the roller 3 is pushed to the right. The ring 1 is taken out of a heating oven 14, the next ring 1 is charged therein, and the same step is repeated.