A bending apparatus includes a shape sensor (23) including a light source (24), an optical fiber (25) configured to propagate desired detection light which is radiated from the light source (24), a detecting part (26) disposed at a part of the optical fiber (25), and a light receiver (27) configured to detect the detection light propagated through the optical fiber (25), the shape sensor (23) being configured to utilize a variation in optical characteristics, which is detected by the detecting part (26) in accordance with a variation of curvature of the optical fiber (25) when the optical fiber (25) is bent, and the shape sensor (23) being freely bendable in any direction and having directivity in detection sensitivity for a bending direction and a bending direction restriction mechanism (12) which is combined with the shape sensor (23) and has bending directivity including such a property of ease in bending that bending is easy in at least a specific direction other than a direction of a center line, and such a property of difficulty in bending that bending is difficult in directions other than the specific direction.
