Provided is a medical instrument that grips a wire having a curved cross-section, including: a sheath which has a center axis； and a holding portion which is arranged to be capable of advancing and retracting in a lumen of the sheath and includes a first holding portion with a first protrusion portion protruding inward in a radial direction of the sheath and a second holding portion with a second protrusion portion protruding inward in the radial direction of the sheath, wherein the first holding portion and the second holding portion are arranged with a gap therebetween so that the first protrusion portion and the second protrusion portion face each other, and wherein when the wire is positioned between the first protrusion portion and the second protrusion portion, the wire comes into point-contact with the first protrusion portion and the second protrusion portion.
