The objective is to control a movement velocity of an endoscope in a body in response to an amount of insertion of the endoscope in view of safety without influence of a strong magnet. A velocity-control computation section 48 adjusts a velocity of an imager to be changeable in response to an amount of insertion of the imager of the endoscope in a body by computing a target velocity vector Vxy. Thereby, increasing of the insertion amount of the imager of the endoscope inserted in the body in a movement direction makes a target velocity vector Vxy of the imager of the endoscope larger. Decreasing of the insertion amount of the imager of the endoscope, or pulling the imager of the endoscope out of the body, makes a target velocity vector Vxy of the imager of the endoscope smaller.