The purpose of the present invention is to enable bending without excessively increasing the tensile force that acts on a motive-power transmission member penetrating through a lumen, and to appropriately operate a movable portion in accordance with a bent form. A manipulator system (1) according to the present invention is provided with: a manipulator (3); an operation unit (2); and a control unit (4) that controls the manipulator (3). The manipulator (3) is provided with: a movable portion; a drive unit that generates motive power to be supplied to the movable portion; a long, thin flexible elongated guide member to which the movable portion and the drive unit are attached at opposite ends thereof; and a motive-power transmission member that transmits the motive power to the movable portion. The elongated guide member is provided with: a long, thin flexible guide tube that has a lumen through which the motive-power transmission member penetrates in a longitudinal direction thereof; and an outer sheath that covers an outer circumference of the guide tube and that has higher rigidity than the guide tube. A proximal end of the outer sheath is attached so as to be movable with respect to the drive unit in the longitudinal direction of the guide tube, and the control unit (4) changes a control parameter in accordance with a moving amount of the outer sheath.