To provide a means capable of efficiently repairing a fine casting defect formed in a disk of a vehicular wheel without conducting correction processes by filling putty, sandpapering and using a lathe or without applying large load to these processes.

The jig for the surface layer process is provided with a bottom plate part 62, a collar wall part 63 provided in a circumferencial manner on the bottom plate part 62, a container member 61 having a protruding shaft part 64 provided at the center of the collar wall part 63 and five sub-protruding shaft parts 65 provided around the protruding shaft part 64, a fastening member for fixing the vehicular wheel to the container member 61 and a processing material stored in a space surrounded by the bottom plate part 62 and the collar wall part 63.