Abstract: An induction furnace, according to one embodiment of the invention, includes an induction heating system and a chamber that comprises a steel cylinder, a top and bottom covers for that seal the top and bottom ends of the cylinder, and coolant passages within the cylinder and the covers. The induction heating system includes a power supply and a coil. The coil surrounds the chamber and is hollow to allow flow of coolant therethrough. A susceptor in the chamber and that is susceptible to induction heating includes top and bottom pieces. A thermal insulator disposed between the susceptor and the inner walls of the chamber comprises a fused quartz cylinder within which the susceptor and the workpiece are contained. The thermal insulator can also include infrared reflectors and insulating members on the ends of the susceptor to reduce heat leakage to parts of the system outside of the susceptor.