Coated cubic boron nitride sintered body tool

A coated cubic boron nitride sintered body tool which is a coated cubic boron nitride sintered body tool at least whose blade edge comprises a coated cubic boron nitride sintered body where the surface of a cubic boron nitride sintered body substrate is coated with a coating layer, wherein;

• (1) the coating layer includes a lower layer and an upper layer, the lower layer being closer to the substrate than the upper layer, and an intermediate layer formed between the lower layer and the upper layer;
• (2) the upper layer has an average thickness of 0.5 to 3.0 μm and comprises a compound represented by a compositional formula Mα, where M represents at least one element selected from Ti, V, Zr, Nb, Mo, Al and Si, and α represents at least one element selected from C, N, B and O;
• (3) the lower layer has an average layer thickness of 0.5 to 3.0 μm and is an alternately laminated material in which a first thin layer having an average layer thickness of 60 to 200 nm is alternately laminated with a second thin layer having an average layer thickness of 60 to 200 nm, wherein:
• (a) the first thin layer comprises a compound represented by the compositional formula (Ti(1-x)Lx)β, where L represents at least one element selected from Al, B and Si, x represents an atomic ratio of L based on the sum of Ti and L, and satisfies 0.01≦x≦0.7, and β represents at least one element selected from C and N, and
• (b) the second thin layer comprises a compound represented by the compositional formula (Al(1-y)Jy)γ, where J represents at least one element selected from Ti, V, Cr, Zr, Nb and Mo, y represents an atomic ratio of J based on the sum of Al and J, and satisfies 0.1≦y≦0.5, and γ represents at least one element selected from C and N;
• and
• (4) the intermediate layer is a metal layer having an average layer thickness of 5 to 100 nm and formed of the same elements found in component M of the upper layer.