The present invention is provided with a robot main body (2) and with a robot-main-body drive mechanism (51). The robot main body includes: a hollow flexible shaft (25) hollow bending joints (27, 28) that can bend in a direction that is orthogonal to the axis thereof and that have a proximal end (27a) that extends from a distal end (25b) of the flexible shaft a wrist joint (30) that can rotate around the axis thereof and that extends from a distal end (28b) of the bending joints an end effector (22) that is attached to the wrist joint a hollow, flexible torque-transmission tube (44) that is inserted through the flexible shaft and the bending joints and that has a distal end (44b) that is attached to the wrist joint and bending-joint-operating cables (41, 42) that are inserted through the flexible shaft and that have a distal end that is attached to the bending joints. The robot main body is configured such that the bending joints bend as a result of the bending-joint-operating cables moving in the extension direction of the bending-joint-operating cables. The robot-main-body drive mechanism includes: a flexible guide pipe (6) that has the flexible shaft inserted therethrough bending-joint drive units (35, 36) that use the drive force thereof to make the bending-joint-operating cables move in the extension direction of the bending-joint-operating cables and a wrist-joint drive unit (38) that uses the drive force thereof to rotate a proximal end of the torque-transmission tube.Selon linvention un corps principal de robot (2) contient : un arbre flexible (25) creux doté dune flexibilité des articulations de courbe (27, 28) creuses dont une extrémité proche (27a) est couplée à une extrémité éloignée (25b) de larbre flexible, et permettant une courbure dans une direction perpendiculaire à leur ligne axiale une articulation de poignet (30) couplée à une extrémité éloignée (28b) des articulations de courbe, et capable dexercer une rotation autour de sa ligne axiale un e