To reduce abrasion due to plastic deformation of a tip edge and obtain a favorablel life in high speed intermittent cutting by containing specified weight % Zr and/or Hf in a substrate.

A cemented carbide to be used is obtained by adding 0.05-0.5wt% Zr and/or Hf to a substrate. Thus, Zr and/or Hf is added to mostly penetrate into B-1 type solid solution phase and binder phase of the cemented carbide, thereby preventing plastic deformation of a tip edge especially affected by cutting heat during cutting. The surface part of the substrate has a Vickers hardness 70-90% of the Vickers hardness of the enough inner side of the substrate, Zr an/or Hf is dissolved and/or dispersed in the substrate surface layer part, and B-1 type solid solution phase is dispersed, decreased and/or made zero to compensate for the defective resistance.