Curvature radius of long tool

Patent Pending PROBLEM TO BE SOLVED: To provide a measuring device which measures the curvature radius of a long tool at high velocity and high precision, and also to provide its method. ; SOLUTION: A line camera 20 is set facing a long tool 11 in a direction orthogonal to the longitudinal direction. A camera stage 50 comprises: a X-axis moving stage 52 driving the line camera 20 in parallel to the longitudinal direction of the long tool; and a Y-axis moving stage 53 focusing the line camera on the long tool edge 11. The line camera 20 is mounted on the camera stage 50.