Patent ID: 8419765

Claim:
A medical instrument comprising: a swingable operating section formed of a pair of forceps, each of which rocks individually around a first axis corresponding thereto; a tubular sheath having a distal end portion situated on a proximal end side of the operating section, the distal end portion having a circular-section portion having a circular cross section perpendicular to a longitudinal central axis of the tubular sheath and a pair of parallel flat portions symmetrically formed on opposite sides of the circular-section portion and in sliding contact with respective proximal end portions of the forceps; a pair of manipulators which advance and retreat along the longitudinal central axis of the tubular sheath, thereby rocking the forceps around the first axis; and a pair of junctions which respectively connect each of the pair of manipulators to a corresponding end portion of one of the pair of forceps, wherein each of the junctions is rotatable around a second axis, wherein each of the junctions is situated on a reference plane containing the longitudinal central axis of the tubular sheath and extending parallel to the second rocking axes, when the operating section is closed.