The purpose of the present invention is to provide a cautery needle device in which the flexibility of an injection needle is not deteriorated even if an electrode constituted by a distal end section of the injection needle is made long, and cooling can be performed during cauterization such that variation in the cooling along the longitudinal direction of the electrode is small. This cautery needle device is provided with: a hollow needle (10) composed of a proximal end section (12) that is insulation-coated and a distal end section (11) that constitutes an electrode； a hub (20) having an injection port and a discharge port for a liquid； a connector (30) for conducting electricity； a thermocouple (40)； and cooling-liquid introduction pipes (51, 52) which extend into the hollow needle (10) such that the respective proximal ends thereof are positioned inside the distal end section (11) of the hollow needle (10), and which discharge from respective distal end openings, a liquid injected from the injection port, wherein a slit is formed in the distal end section and a front region of the proximal end section (12) of the hollow needle (10) and imparts flexibility, liquid-tightness is achieved inside the hollow needle (10), and the positions of the distal end openings of the cooling-liquid introduction pipes (51, 52) differ from each other in the front/rear direction of the hollow needle (10).本發明是以提供一種燒灼用針裝置，即使藉注射針前端部所構成的電極較長，仍無損於注射針的撓性，在燒灼時，在電極的長度方向可進行不均勻性少的冷卻為目的。此燒灼用針裝置，具備：中空針(10)，係由絕緣包覆的基端部(12)與構成電極的前端部(11)所構成；輪轂(20)，具有液體的注入埠及排出埠；通電用連接器(30)；熱電偶(40)；及冷卻用液體導入管(51，52)，延伸於中空部(10)的內部且各個的前端位於中空針(10)的前端部(11)的內部，使得從注入埠注入的液體由各個的前端開口吐出，在中空針(10)的基端部(12)的前端區域及前端部形成有開縫並賦予撓性，確保中空針(10)之內部的液密性，使冷卻用液體導入管(51，52)的前端開口位置在中空針(10)的前後方向彼此不同。
