To provide a metal plate conveying system which can efficiently convey a metal plate by alternative operation etc. of two loaders and furthermore conveys the metal plate without causing a projected working tool provided on a loader on one side to interfere a workpiece holder.

A metal plate conveying apparatus 2 has before and behind loaders 13, 14 which can traveled independently, the loader 13 on the before side has working tools 58, 59 which are projected forward. A conveyance controller 70 uses the two loaders 13, 14 alternately as a basic conveying pattern for carrying-out the metal plate W from a metal plate working machine 1. The metal plate which is in the vicinity of the workpiece holder 57 and not larger than the set dimension among the metal plates W is controlled so as to release the basic conveying pattern and to be conveyed by the loader 14 on the behind side, which has no working tools 58, 59.