An articulating structure that bends by relative movement of a plurality of segments connected in series, includes a first segment and a second segment arranged in contact with each other, wherein the first segment has a first front rolling contact surface, and the second segment has a second rear rolling contact surface in line contact with the first front rolling contact surface on a first direction contact line, the first segment has a projection protruding forward from the first front rolling contact surface, and the second segment has a coupling element recessed in the second rear rolling contact surface, wherein the projection is inserted into the coupling element, the first segment and the second segment make a relative rolling movement for translation of the first direction contact line while maintaining the line contact, and the projection supports the first segment and the second segment for the first direction.