A passive bending section 24 for an endoscope 10 is disposed between an active bending section 23 of an inserting section 20 and a flexible tube 25 of the inserting section 20 and is passively bent by receiving an external force. In the passive bending section 24, a curvature gradually increases from the distal end portion of the passive bending section 24 toward the proximal end portion of the passive bending section 24.