A medical cutting instrument which stably exhibitshigh joint strength obtained by brazing. A cuttinginstrument (A) is configured by providing a working section(2) to the front end of a shank section (1), the workingsection (2) consisting of a carbide or a ceramic, the shanksection (1) being constructed from a round stainless steelbar or a round tool steel bar. The shank section (1) andthe working section (2) are connected through a brazedsection (3). The brazed section (3) is the portion at whichthe shank section (1) and the working section (2) arebrazed together while brazing surfaces, which are providedwith protrusion sections formed on the shank section (1)and/or the working section (2), are caused to be in contactwith each other. The protrusion sections provided on thebrazing surfaces each comprise sloped surfaces (5b) havingan apex (5a), and the height of the sloped surfaces (5b) isset in the range of 0.5%-8%, inclusive, of the diameter ofthe brazing surface of the shank section (1).
