The present invention improves the strength of the bottom (net) of the jig and makes it more difficult and unlikely for deviation of the mesh to occur.A workpiece is loaded on the net (2) of the heat treat furnace jig (hereinafter, heat treatment furnace jig). In the net (2), a first strand (10), a second strand (20) and a third strand (30) are in contact at a contact point (X1). Near the contact point (X1), the second strand (20) overlaps the first strand (10) from above and the third strand (30) overlaps the first strand (10) from below. As a result, the first strand (10) is held between the second strand (20) and the third strand (30) in the up/down directions.