NOVELTY - A die for forming a honeycomb structure comprises a die base obtained by stacking and bonding two plate-like members together to obtain a die precursor having honeycomb-shaped slits on one surface and back holes on another surface. The plate-like components include a first component made of a tungsten carbide-based super hard alloy containing tungsten carbide and a second component made of phase transformation-causing metal material.    USE - For forming a honeycomb structure (claimed) for use in e.g. a catalyst carrier utilizing a catalyst function for an internal combustion engine, a boiler, a chemical reaction apparatus, a reforming unit for a fuel battery or the like, a particulate capturing filter in an exhaust gas.    ADVANTAGE - The invention provides a high formability and superior wear resistance. Since portions of a die base provided with slits are superior in resistance to wear, cost reduction of the honeycomb structure to be formed can be realized.    DETAILED DESCRIPTION - A die (1) for forming a honeycomb structure comprises a die base (2) having two surfaces, wherein one surface is provided with slits (5) of a honeycomb shape and the other is provided with back holes (6) which communicate with the slits and introduce a forming material being extruded from the slits to form the honeycomb structure. The die base is obtained by stacking and bonding two plate-like components (3, 4) together to obtain a die precursor, and providing the slits and the back holes in the die precursor. The two plate-like components constituting the die precursor are a first component which is the one surface (7) of the die base and is made of a tungsten carbide-based super hard alloy containing at least tungsten carbide, and a second component which is the other surface (8) of the die base and is made of a metal material capable of causing martensite transformation, bainite transformation, and/or pearlite transformation by cooling of an austenite phase. Tensile and compressive stresses in a mutually bonded surface of the two plate-like members constituting the die precursor are less than or equal to1000 MPa. An INDEPENDENT CLAIM is also included for a method of manufacturing a die for forming a honeycomb structure comprising stacking and bonding a plate-like first component made of a tungsten carbide-based super hard alloy containing at least tungsten carbide, and a plate-like second component made of a metal material capable of causing at least one of three phase transformations of martensite transformation, bainite transformation, and pearlite transformation by cooling of an austenite phase while heating these components at a temperature not less than a temperature at which the second component causes austenite transformation; and lowering a temperature of the bonded first and second components at a predetermined temperature drop rate to a temperature to start at least one phase transformation of the three phase transformations caused by the second component, thereby allowing the metal material constituting the second component to cause at least one of the three phase transformations in such a manner that tensile and compressive stresses remaining in a bonded surface between the first and second components are less than or equal to1000 MPa to obtain the die precursor in which the first and second components are stacked and bonded together.    DESCRIPTION OF DRAWING(S) - The figure shows a perspective view of a die for forming a honeycomb structure.    Die (1)    Die base (2)    Plate-like components (3, 4)    Slits (5)    Back holes (6)    Surfaces (7, 8)    Bonded surface (9)    Plane (A)