To provide a novel jig that prevents adhesion to a material to be burned and reduces the contamination of the material to be burned, as the jig used for burning a metallized aluminum nitride substrate having a wiring pattern made of tungsten and an insulating pattern made of aluminum nitride in a part on the wiring pattern.

This jig comes into contact with the material to be burned in a process of burning the metallized aluminum nitride substrate having the wiring pattern made of tungsten and the insulating pattern made of aluminum nitride in a part on the wiring pattern. The burning is performed using the jig where at least the surface coming into contact with the material to be burned is composed of a composite surface of aluminum nitride and tungsten in which aluminum nitride is made to exist at an area percentage of 15-35%.