Provided is a medical treatment tool capable of satisfactorily performing treatment such as coagulation and hemostasis, and treatment such as surgery. The treatment portion 30 of the medical treatment instrument 1 includes first and second forceps members 31 and 32. The forceps members 31 and 32 constitute a pair of electrodes capable of forming an electric field between them. The first forceps member 31 includes a pair of first forceps portions 31a and 31a facing each other in the facing direction orthogonal to the extending direction. The second forceps member 32 is rotatable relative to the first forceps member 31 within an angular range in which the second forceps member 32 can enter and leave the gap 39 between the first forceps portions 31a and 31a around the rotation axis L5 along the facing direction. It has become.凝固や止血を含む治療、手術等の処置を良好に行うことのできる医療用処置具を提供する。医療用処置具１の処置部３０は、第１、第２鉗子部材３１，３２を含む。これら鉗子部材３１，３２は、互いの間に電場を形成可能な一対の電極を構成する。第１鉗子部材３１は、延び方向と直交する対向方向に対峙する一対の第１鉗子部３１ａ，３１ａを含む。第２鉗子部材３２は、上記対向方向に沿う回転軸線Ｌ５のまわりに、第１鉗子部３１ａ，３１ａどうし間の間隙３９に出入り可能な角度範囲で、第１鉗子部材３１に対して相対回転可能になっている。
