To accurately and efficiently instruct the repair range of a defect with a simple configuration.

A metal plate where product information is sent from a host computer 11 is placed by matching a longitudinal side surface to an X axis being used as the side end part of a transfer truck. The transfer truck where the metal plate is placed is allowed to travel, and the surface of the metal plate is subjected to slit image pickup by a zero-point signal being detected by a zero-point dialing device 3 and a distance pulse signal from a travel pulse dialing device 4. A defect information-processing device 5 displays an image for indicating the state of the surface of the metal plate according to an image signal whose image is picked up in reference to X and Y axes, and specifies the coordinates of a defect repair range being specified by a key input.