A heat treatment apparatus includes a plurality of induction heating devices
which
heat a steel product, a correctional device which corrects the steel product, a
computing device which computes supply predetermined electric power which is supplied
to the induction heating device, on the basis of a size of the steel product, a
conveying speed of the steel product, a heating target temperature of the steel
product, and a predetermined temperature of the steel product at the previous stage
of the induction heating devices, and a power supply unit which supplies the supply
predetermined electric power computed by the computing device to the induction
heating devices, and the computing device which computes electric power for uniform
heating processing on the steel product or electric power for surface layer heating
processing on the steel product.
