Medical instrument for endoscope

摘要

A medical instrument for an endoscope according to the invention is the medical instrument to be used in the endoscope by being inserted therein, and the medical instrument includes: a flexible elongated sheath having a first lumen; a conductive wire which is inserted into the first lumen and of which a portion of a distal side is exposed to the outside of the sheath as an instrument unit; and a balloon which is attached to the sheath and is expandable with the supply of fluid. The balloon is configured such that an axial dimension thereof is larger than a radial dimension upon expansion and a distal end of the balloon upon expansion is located closer to a proximal side than the treatment unit exposed from the sheath.