A holding member producing device is provided. A first inclined surface including inward as they separate from a bottom surface is formed on an outer side surface of an arm portion. For this reason, when a first die and a second die having an opening/closing direction which matches with a plate thickness direction of the bottom surface are opened, the locking projections can easily cross over steps by outwardly bending and deforming the arm portions. Therefore, it is possible to suppress damage, projection sizes of locking projections can be increased, and it becomes easy to hold a fuse.