A medical cutting instrument which stably exhibits high joint strength obtained by brazing. A cutting instrument (A) is configured by providing a working section (2) to the front end of a shank section (1), the working section (2) consisting of a carbide or a ceramic, the shank section (1) being constructed from a round stainless steel bar or a round tool steel bar. The shank section (1) and the working section (2) are connected through a brazed section (3). The brazed section (3) is the portion at which the shank section (1) and the working section (2) are brazed together while brazing surfaces, which are provided with protrusion sections formed on the shank section (1) and/or the working section (2), are caused to be in contact with each other. The protrusion sections provided on the brazing surfaces each comprise sloped surfaces (5b) having an apex (5a), and the height of the sloped surfaces (5b) is set in the range of 0.5%-8%, inclusive, of the diameter of the brazing surface of the shank section (1).
