Patent ID: 8753337

Claim:
A monopolar diathermic cutter comprising: a cylindrical main body member including a tip end portion consisting of an electrically insulating portion; an elongated first electrode including a first diameter, a central axis and a tip end projecting from the tip end portion of the cylindrical main body member, the elongated first electrode being movably inserted in the cylindrical main body member; a second electrode including a second diameter which is larger than the first diameter, disposed on the tip end of the elongated first electrode such that the second electrode faces the tip end portion of the cylindrical main body member, extending in a direction deviating from the central axis of the elongated first electrode, and including a base-end surface opposed to the tip end portion of the cylindrical main body member; and an electrically insulating member with which the second electrode is coated in such a manner that at least a part of the base-end surface of the second electrode is exposed, wherein: the elongated first electrode has electrically conductive properties and is configured to cut living tissue, the second electrode is electrically connected to the elongated first electrode to form a single electrode member, the second electrode extending in the direction deviating from the central axis of the elongated first electrode is configured to come close to and come away from the electrically insulating portion and includes a side surface portion with respect to the central axis of the elongated first electrode, the side surface portion of the second electrode is located inward of an outermost side surface of the electrically insulating member; and the central axis for all portions of the elongated first electrode projecting distally from the tip end portion of the cylindrical main body member corresponds to a central axis of the cylindrical main body member.