PROBLEM TO BE SOLVED: To improve torque transmission in a catheter capable of grasping a position using a magnetic field. SOLUTION: A catheter includes a coil body formed by winding a conductive wire in the circumferential direction of the catheter, and a conductor formed of a material arranged inside or outside the coil body and having conductivity. A first insulating portion that is arranged between the coil body and the conductor and electrically insulates the coil body and the conductor, and electrically connects the base end side of the coil body to the power supply or the electric signal detector. It includes a connecting portion and a second connecting portion that electrically connects the base end side of the conductor and the power supply or the electric signal detector. The coil body is arranged on the tip side of the coil body and is electrically connected to the tip side coil portion arranged on the distal end side of the coil body and adjacent to each other, and adjacent to each other. Includes the base end side coil portion in which the strands are in contact with each other. The tip side of the tip side coil portion and the tip side of the conductor are electrically connected. [Selection diagram] Fig. 2【課題】磁場を用いた位置の把握が可能なカテーテルにおいて、トルク伝達性を向上させる。【解決手段】カテーテルは、導電性を有する素線をカテーテルの周方向に巻回して形成されたコイル体と、コイル体の内側又は外側に配置され導電性を有する材料により形成された導電体と、コイル体と導電体との間に配置されコイル体と導電体とを電気的に絶縁する絶縁部と、コイル体の基端側と電源又は電気信号検出器とを電気的に接続する第１接続部と、導電体の基端側と電源又は電気信号検出器とを電気的に接続する第２接続部とを備える。コイル体は、コイル体の先端側に配置され隣り合う素線間が離間した先端側コイル部と、コイル体の基端側に配置され先端側コイル部に電気的に接続されると共に、隣り合う素線間が接触した基端側コイル部とを含む。先端側コイル部の先端側と導電体の先端側とは電気的に接続されている。【選択図】図２
