Knife for use in medical treatment

A medical knife having an edge formed along the periphery of a cutting part, comprising:

• a flat projection shape of the cutting part is formed in an approximate rhomboid shape configured by a front end part including a pointed end formed on a front end portion of the cutting part and the vicinity of the pointed end, a widest part with the largest width, and a side surface part formed between the front end part and the widest part,
• a front side bevel constituting an edge on the front side and a back side bevel constituting an edge on the back side are individually formed, having as a boundary a virtual surface including the edge formed along the periphery of the cutting part, and
• the ratio of the angle between the virtual surface and the back side bevel to the angle between the virtual surface and the front side bevel at the front end part is greater than the ratio of the angle between the virtual surface and the back side bevel to the angle between the virtual surface and the front side bevel at the side surface part.