PURPOSE: To suppress deformation and wear of the material contacting part of a die and to suppress deformation of a die itself.

CONSTITUTION: An alloy ring 20 made of Ni base or Co base heat resistant alloy is tightly fitted on the inner surface side from an approach zone (a) through bearing zone (b) on the inner side of a die base body 10 made of alloy tool steel. A back up ring 30 made of alloy tool steel is shrinkage fitted at the inner side of a relief zone C of the die base body 10, preventing the alloy ring 20 from pushing out forward on the extruding direction. The alloy ring 20 is prevented from being pushed out backward on the extruding direction by making the outer surface of the alloy ring 20 a taper surface, contracting toward backward on the extruding direction.