To prevent the overheating of the fingers of a gate and to prevent the fusion of scraps to the fingers.

Inside a tower body 21 provided with a scrap charging gate 22 at an upper edge part of it and a scrap discharging gate 23 opposing the scrap feeding gate 12 of the furnace cover 3 of a blast furnace at a lower edge part of it, a preheating chamber formed at the upper part of a gate 25 arranging an air permeable and openable gate 25, a duct 31 having an exhaust gas intake gate facing the exhaust gas gate 13 of the blast furnace at the lower part of it connected to the side wall part of the preheating chamber, a gas discharging duct 38 connected to the exhaust gas exhausting path 41 sucking and discharging the exhaust gas connected to the side wall 21 a of the tower body on the under side of the preheating chamber installed part and a shutter 60 opening and closing the inside of the tower body at the position between the exhaust gas duct 38 connecting part and the scrap discharging gate 23 are provided.