A metallic roof material 1 according to the present invention comprises: a front substrate 10 made of a metal sheet, the front substrate 10 comprising a body portion 100 formed into a box shape; a back substrate 11 arranged on a back side of the front substrate 10 so as to cover an opening of the body portion 100; and a core material 12 filled between the body portion 100 and the back substrate 11, the metallic roof material 1 being tightened to a roof base by driving at least one tightening member into the body portion 100, wherein a top plate portion 101 of the body portion 100 comprises at least one protruding rib 3 comprised of at least one protrusion 30 disposed along a side of a polygon or along a circle, and wherein the metallic roof material 1 is configured such that the tightening member is driven into an inner region 3a of the protruding rib 3.