PURPOSE: To selectively and partially modify a sintered alloy so as to make anti- wear property, impact resistance and coagulation resistance excellent, in a sintered alloy having a surface bonding phase such as a tool, by securing a substance having strength higher than that of the bonding phase and an inert substance to said surface bonding phase part.

CONSTITUTION: A sintered alloy for a cutting tool is formed of a hard phase comprising one or more of carbide, nitride, boride, silicide and oxide of a metal belonging to the Groups 4a, 5a, 6a or a mutual solid solution thereof, and a bonding phase comprising one or more of Co, Ni, Fe, Mo, Cr or W. A substance having hardness higher than that of the bonding phase and an inert substance are secured to the bonding phase part present in the surface layer of said sintered alloy by an ion injection method or a mechanical method to selectively and partially modify the surface of the sintered alloy. The substance to be secured is selected from high density boron nitride, boron carbide, silicon nitride, silicon carbide, aluminum oxide and aluminum nitride.