PURPOSE: To provide the position detection display device of an insertion tool capable of precisely detecting and displaying the position by only fitting a simple member to the in vivo insertion tool such as a therapeutic apparatus or an endoscope.

CONSTITUTION: Multiple signal members 7, 8, 9 are provided on a therapeutic apparatus 1 inserted into an organism 3, and multiple receiving members 11, 12 detecting the positions of the signal members 7, 8, 9 in no contact with the therapeutic apparatus 1 are provided. Mark members 4, 5, 6 made of a material detectable by the tomographic equipment such as CT or MRI and serving as reference coordinate marks during tomography are provided. The position of the therapeutic apparatus 1 inserted into the organism 3 is estimated based on the positions of the multiple signal members 7, 8, 9, the position is converted into the position in the reference coordinate of a tomographic image, and this position is overlapped on the tomographic image and displayed.