A reduced iron discharging screw conveyer is provided in a rotary hearth furnace and discharges reduced iron out of the rotary hearth furnace. The rotary hearth furnace produces the reduced iron by charging and heating a pellet including metallic oxide and coal material onto a rotary hearth rotating in a horizontal plane. The reduced iron discharging screw conveyer has a rotary shaft and a screw blade which is spirally formed on an outer surface of the rotary shaft. A lead angle θ of the screw blade 5a satisfies a condition of “0.46 rad ≦θ≦0.79 rad”. A ratio (h/D) between height h of the screw blade and an outer diameter D of the screw conveyer is smaller than 0.2, and a ratio (t/h) between thickness t and height h of the screw blade is larger than or equal to 0.12.