A bending apparatus includes a shape sensor including a light source, an optical fiber, a detecting part, and a light receiver. The shape sensor utilizes a variation in optical characteristics, which is detected by the detecting part in accordance with a variation of curvature of the optical fiber when the optical fiber is bent. The shape sensor is freely bendable in any direction and having directivity in detection sensitivity for a bending direction. A bending direction restriction mechanism is combined with the shape sensor 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.