[Problem to be solved by the Invention] To provide a highly safe medical device which can suppress careless application of electric energy. [Means for solving the Problem] A hand-side steering unit 70 which is provided at a proximal portion of a catheter and which steers advance and retraction operation of a heating unit at a distal end includes: a main body portion 71 interlocked with the catheter a slide portion 100 interlocked with the heating unit and approachable and separable with respect to the main body portion 71 a guide unit 40A interlocked with the main body portion 71 movably and concurrently fixed to the slide portion 100 and an input connector 75 provided at the main body portion 71, electrically connected with the heating unit and concurrently with which an output connector for supplying electric energy is connectable, wherein the guide unit 40A is arranged at a position for hindering connection between the input connector 75 and the output connector, and also there is provided a cutout portion 41 (connection adjusting unit) which enables connection between the input connector 75 and the output connector when the guide unit 40A moves with respect to the main body portion 71 and the heating unit moves to a position at which the biological tissue is heatable.
