A heat-absorbent and radiant steel sheet according to the present invention has a steel sheet, and a hot-dipped plating layer arranged on the surface thereof. The emissivity of the heat-absorbent and radiant steel sheet is 0.4 or greater. The hot-dipped plating layer includes Zn, 1.0-22.0 mass% of Al, 1.3-10.0 mass% of Mg, and an oxide and/or hydroxide having lattice defects and distributed in a lamellar form. A heat-absorbent and radiant member according to the present invention is constituted of the aforementioned heat-absorbent and radiant steel sheet.