[Problem] To provide a coil body and medical apparatus using said coil body which is capable of ensuring the sufficient torque transmissibility.[Solution] A coil body (30) comprises a first layer (32) which is formed by first wires (32a) wound in a spiral shape, and a second layer (34) which is provided on an outer periphery of the first layer (32) and is formed by second wires (34a) wound in a spiral shape. Furthermore, a tensile strength of first wires (32a) is greater than a tensile strength of second wires (34a).