To provide a cutting tool and a manufacturing method thereof, capable of restraining a DLC layer from separating from a blade part, while smoothing a surface of the blade part after forming the DLC layer.

A smooth surface 31 is formed in advance on a surface of a recess 3, and surface roughness of the recess 3 is reduced, and a recess 32 is formed to the smooth surface 31 small in surface roughness. Thus, surface roughness of a blade part 3 after forming the recess 32 can be reduced, and as a result of it, a surface of the blade part 3 after forming the DLC layer 40 can be smoothed. The recess 32 is also formed on the surface of the blade part 3, so that the surface area of the blade part 3 can be largely secured, and since the anchor effect by the recess 32 can be exhibited, the DLC layer 40 can be restrained from separating from the blade part 3.