PURPOSE: To prevent the machining from being started by an erroneous tape in case the set position is wrong, by providing an apparatus for comparing video pattern of a work taken by video cameras with video patterns of the work taken previously.

CONSTITUTION: The characteristic outer configuration of the work 3 on a pallet 2 that has reached to a pallet delivering position to an M/C is taken by the video cameras 12, 13, 14. On the other hand, the video patterns taken by the video cameras 12, 13, 14 are compared with the video patterns 15 of the work previously taken by a video comparing apparatus 16. When the patterns coincide respectively, a tape machining start signal 17 is issued, whereas if they do not coincide, a tape machining stop signal 18 is issued, so that the work can be prevented from being machined by a wrong tape.