This paper presents an automation scheme of an overhead magnet crane that is used as an essential part of storage yard automation. First, load cells are introduced to detect the number of lifted steel plates. Then a current control algorithm to lift the right number of steel plates is proposed and implemented by using the on-line tuning look-up table. Finally, the overall hardware and software description for automatic crane operation is presented. The results have been successfully implemented on POSCO’s No.2 thick steel plate storage yard.