PURPOSE: To make long and consecutive heat air treatment at more than 1,100C possible by fabricating the blades, which comprises the gas blowing section, the insert leg to blade wheel section, and the flange section which is in between the former two, with ceramics.

CONSTITUTION: The blade 1 comprises the gas blow section 6, the leg section 5 to be inserted to blade wheel 2, and the flange section 7 which is inbetween the others. The whole blade is made of ceramics by solid forming which have heat resistance of more than 1,200C and tensile strength of more than 100kg/cm2 at the working temperature. The ceramics suitable for this ceramic fan blade are sintered silicon nitride or silicon carbide, and are made by non-pressurized sintering. Thus, by using this blade, heat air treatment at more than 1,100C can be done for long and consecutively, and heating efficiency can be improved.