Provided is a defibrillation catheter that can, by approaching from the inferior vena cava, arrange a first DC electrode group attached to a distal end portion of a tube member inside the coronary sinus and arrange a second DC electrode group inside the right atrium. The defibrillation catheter is provided with: a first DC electrode group (31G) and a second DC electrode group (32G) that are attached to a tube member (10)； and a first operation wire (71) and a second operation wire (72) for causing the distal end portion of the tube member to bend in both directions. When the rear end of the first operation wire is pulled to the maximum limit in a state in which bending of the tube member is inhibited on the proximal end side of a distal end position of the second DC electrode group, a bend angle ([Theta]1) of the distal end portion of the tube member is approximately 270 DEG. When the rear end of the second operation wire is pulled to the maximum limit in a state in which bending of the tube member is inhibited on the proximal end side of the distal end position of the second DC electrode group, a bend angle ([Theta]2) of the distal end portion of the tube member is approximately 90 DEG.一種心腔內除顫導管，係具備有被裝著於管構件(10)處之第1DC電極群(31G)以及第2DC電極群(32G)、和用以使管構件之前端部分朝向兩方向而撓折之第1操作用鋼線(71)以及第2操作用鋼線(72)，當在對於較第2DC電極群之前端位置而更靠基端側處的管構件之撓折作了抑制的狀態下而將第1操作用鋼線之後端作了最大限度之拉張時，管構件之前端部分之撓折角度(θ1)，係為略270°，當在對於較第2DC電極群之前端位置而更靠基端側處的管構件之撓折作了抑制的狀態下而將第2操作用鋼線之後端作了最大限度之拉張時，管構件之前端部分之撓折角度(θ2)，係成為略90°。若依據此除顫導管，則藉由從下大靜脈起之進入(approach)，係能夠將被裝著於管構件之前端部分處的第1DC電極群配置在冠狀靜脈竇內並將第2DC電極群配置在右心房內。
