Abstract: In a cutting blade made of a titanium carbonitride-base cermet comprising:3 to 20% by weight of a metal binder phase, the principal ingredients of which are Co and/or Ni,3 to 30% by weight of a single-structural hard phase comprising at least one component selected from the group consisting of carbide, nitride and carbonitride compounds of metal elements belonging to Groups 4a, 5a and 6a of the periodic table and a solid-solution comprising at least two said compounds, andthe balance being a double-structural hard phase which comprises a core portion and a shell portion completely surrounding said core portion, wherein said core and shell portions comprise as substituents titanium carbonitride and/or a carbonitride compound of Ti and at least one element M selected from metal elements belonging to Groups 4a, 5a and 6a of the periodic table other than Ti, except that the shell portion must contain a carbonitride compound of at least M, and wherein said shell portion has a lower content of Ti and a higher conte