This interposition device being the interposition device interposing the medical application linear body (104) to the tube of internal, has with the compression which is measured the Drive device which makes the medical application linear body (104) longitudinal axial direction move by the compression of the longitudinal axial direction operation to (1) and the medical application linear body (104) and the measuring device (60) and the measuring device (60) which measure pulling power and the message device (92 - 94) message pulling power to the operator.この挿入装置は、医療用線状体(104)を体内の管へ挿入する挿入装置であって、医療用線状体(104)を長手軸方向へ移動させる駆動装置(1)と、医療用線状体(104)に作用する長手軸方向の圧縮力および引張力を計測する計測装置(60)と、計測装置(60)によって計測された圧縮力および引張力を術者に通報する通報装置(92~94)とを備える。