The purpose of the present invention is to enable, even in an endoscopic operation, an operation upon a specific operation site while monitoring the overall surgical site, such as an organ. An artificial magnetic field is generated such that a surgical site of a patient is positioned within a generated three-dimensional artificial magnetic field space. A plurality of magnetic sensors are respectively mounted in a plurality of predetermined locations of the surgical site of the patient. Data of a 3-D image of the surgical site and position information of the mounting locations of the magnetic sensors with respect to the surgical site are stored in a storage unit as position information of the mounting locations with respect to the 3-D image of the surgical site.
