An endoscope system (1) includes an end portion (102) of a probe (101) of an endoscope (100) that moves in a subject (900) and a receiving device (200) and a display device (280) that acquire information about the inside of the subject (900) by an imaging element such a CCD array provided at the end portion (102). An external device includes the receiving device (200) the display device (280) a location acquiring unit (220) that acquires a plurality of pieces of location information of the end portion (102) in the subject (900) a trajectory generating unit (231) that generates the movement trajectory of the end portion (102) in the subject (900) based on the pieces of location information a storage unit (202) that stores the standard trajectory and a scale adjusting unit (233) that adjusts the scale of the movement trajectory so that the movement trajectory matches the standard trajectory.
