An endoscope 2 includes a flexible tube section 4 including coiled tubes 4a, 4b, 4c, a motor 72 disposed on a proximal side of the flexible tube section 4, a driving force transmission unit 53 disposed on a distal side of the flexible tube section 4, and a drive shaft 79 provided inside the flexible tube section 4 along a long axis, the drive shaft being caused to perform rotation around the long axis by a driving force of the motor 72 and to transmit the rotation of the motor 72 to the driving force transmission unit 53, where torsional resistance of the flexible tube section 4 around the long axis is set higher than torsional resistance between a relay gear 75 of the motor 72 and a drive gear 55 of the driving force transmission unit 53 through the drive shaft 79.
