The distal (2036) end (11a) with the proximal end (11b) with the sheath which it possesses (11) with, it possesses with the point and the basic edge, in order to become the direction where the direction which from the aforementioned basic edge faces to the aforementioned point from the proximal end faces to the distal (2036) end, it is inserted in the sheath, in the aforementioned point the needle-shaped electrode section which deals with vis-a-vis the object region (50) with, being provided in the aforementioned point of the needle-shaped electrode section, the first electrode which is exposed outside (51) with, relative position relationship with the first electrode being locked by the position where it alienates on the aforementioned basic edge side than the first electrode, it arrangesThe second electrode which is done (52) with, lying between with the first electrode and the second electrode, when the first electrode and the insulator which severs relations with the second electrode (53) with, the first conductive part which turns on electricity high frequency current to the first electrode and, it turns on electricity high frequency current to the second electrode, the second conductive part and, it has.遠位端部(11a)と近位端部(11b)とを有するシース(11)と、先端と基端とを有し、前記基端から前記先端に向かう方向が近位端部から遠位端部に向かう方向となるようにシースに挿入され、前記先端において対象部位に対して処置を行う針状電極部(50)と、針状電極部の前記先端に設けられて外部に露出された第一電極(51)と、第一電極よりも前記基端側に離間した位置に第一電極との相対位置関係が固定されて配置された第二電極(52)と、第一電極と第二電極との間に介在されて第一電極と第二電極とを絶縁する絶縁体(53)と、第一電極に高周波電流を通電させる第一導電部と、第二電極に高周波電流を通電させると第二導電部と、を備える。
