The medical device has a distal end portion having a distal end opening formed therein, is attached to an outer surface of the tubular member that defines a hollow portion having the distal end opening as one end, and can detect contact with living tissue. Puncture capable of projecting from the tip opening in a direction substantially orthogonal to a contact plane that is located in the hollow portion and is in contact with the three or more contact detectors from the distal side. And a member.医療器具は、先端開口が形成されている先端部を有し、前記先端開口を一端とする中空部を区画する管状部材と、前記先端部の外面に取り付けられ、生体組織との接触を検出可能な３つ以上の接触検出部と、前記中空部に位置し、前記３つ以上の接触検出部に遠位側から接する平面である接触平面に略直交する方向に前記先端開口から突出可能な穿刺部材と、を備える。
