As for the over tube which relates to this invention, the aforementioned insertion section of the device which possesses the insertion section which is inserted to internal of the patient being the over tube which guides the aforementioned device to the occasion where insertion or removal leaving it does, to internal of the aforementioned patient, the air-supplied pipe conduit to be formed with the inside of this over tube, and the aforementioned device which is inserted into this over tube as for the aforementioned air-supplied pipe conduit, the air-supplied mouth which is provided on basic edge side of the aforementioned over tube and being formed by the over tube insertion section, the communication hole which supplies air in the windpipe of the aforementioned patient be communicated respectively, the body wall and the description above of the aforementioned patientThrough the aforementioned communication hole, by sealing with the communication holes from the aforementioned air-supplied pipe conduit putting on the windpipe of the aforementioned patient, the 1st seal component which guarantees the windpipe which it communicates, is provided in the peripheral section of the over tube insertion section.本発明に係るオーバーチューブは、患者の体内に挿入される挿入部を有するデバイスの前記挿入部を前記患者の体内に挿入あるいは抜去する際に、前記デバイスを案内するオーバーチューブであって、このオーバーチューブの内面とこのオーバーチューブ内に挿入される前記デバイスとの間に送気管路が形成され、前記送気管路は、前記オーバーチューブの基端側に設けられた送気口と、オーバーチューブ挿入部に形成されて前記患者の気管に送気を行う連通孔とのそれぞれに連通され、前記患者の体壁と前記連通孔との間をシールすることにより前記連通孔を介して前記送気管路から前記患者の気管にかけて連通する気道を確保する第1のシール部材が、オーバーチューブ挿入部の外周部に設けられている。
