To clarify the effectiveness of multi-layer AlCrWN/AlCrWSiN-coated cemented carbide tools, the wear progress was investigated in cutting sintered steel using three types of coated tool. Tool I had a mono-layer (Al60,Cr25,W15)N-coating film, Tool II had a mono-layer (Al53,Cr23,W14,Si10)N-coating film and Tool III had a multi-layer (Al60,Cr25,W15)N/(Al53,Cr23,W14,Si10)N-coating film. The following results were obtained: (1) The main tool failure of the three types of coated tools was flank wear within a maximum value of flank wear width of 0.2 mm. (2) The wear progress of Type III, which was a multi-layer coating system, was the slowest in cutting sintered steel.