A sintering apparatus comprising: a vehicle disposed movably along a traveling path and having a to-be-sintered material loaded therein, the travelling path extending in an anteroposterior direction; a charging unit for charging the to-be-sintered material to the vehicle; an ignition-furnace disposed above the traveling path for spraying a flame to an upper portion of the to-be-sintered material; a plurality of wind-boxes disposed below the vehicle along the traveling path to provide a suction power to the vehicle; a hood disposed above the vehicle and extending along the traveling path, the hood extending in the anteroposterior direction; a circulation unit connected to some of a plurality of the wind-boxes and supplying exhaust gas sucked into said some of the wind-boxes to the hood; and an air supply unit connected to the hood or connected to the hood and the circulation unit to supply air to the to-be-sintered material, wherein the circulation unit includes: a circulation pipe connected to said some of the plurality of the wind-boxes and having an inner space for receiving the exhaust gas therein; a circulation line defining a path along which the exhaust gas moves, wherein one end of the circulation line is connected to the circulation pipe and the other end thereof is connected to the hood; and a blower disposed in the circulation line, characterized in that an opening is defined in a top portion of the hood, wherein the air supply unit includes a door unit mounted on the hood to open and close the opening, wherein the opening is defined forwardly of a central point of the hood in the anteroposterior direction thereof, and the circulation line is formed rearwardly of the central point of the hood in the anteroposterior direction thereof. a vehicle disposed movably along a traveling path and having a to-be-sintered material loaded therein, the travelling path extending in an anteroposterior direction; a charging unit for charging the to-be-sintered material to the vehicle; an ignition-furnace disposed above the traveling path for spraying a flame to an upper portion of the to-be-sintered material; a plurality of wind-boxes disposed below the vehicle along the traveling path to provide a suction power to the vehicle; a hood disposed above the vehicle and extending along the traveling path, the hood extending in the anteroposterior direction; a circulation unit connected to some of a plurality of the wind-boxes and supplying exhaust gas sucked into said some of the wind-boxes to the hood; and an air supply unit connected to the hood or connected to the hood and the circulation unit to supply air to the to-be-sintered material, wherein the circulation unit includes: a circulation pipe connected to said some of the plurality of the wind-boxes and having an inner space for receiving the exhaust gas therein; a circulation line defining a path along which the exhaust gas moves, wherein one end of the circulation line is connected to the circulation pipe and the other end thereof is connected to the hood; and a blower disposed in the circulation line, characterized in that an opening is defined in a top portion of the hood, wherein the air supply unit includes a door unit mounted on the hood to open and close the opening, wherein the opening is defined forwardly of a central point of the hood in the anteroposterior direction thereof, and the circulation line is formed rearwardly of the central point of the hood in the anteroposterior direction thereof. a circulation pipe connected to said some of the plurality of the wind-boxes and having an inner space for receiving the exhaust gas therein; a circulation line defining a path along which the exhaust gas moves, wherein one end of the circulation line is connected to the circulation pipe and the other end thereof is connected to the hood; and a blower disposed in the circulation line, characterized in that an opening is defined in a top portion of the hood, wherein the air supply unit includes a door unit mounted on the hood to open and close the opening, wherein the opening is defined forwardly of a central point of the hood in the anteroposterior direction thereof, and the circulation line is formed rearwardly of the central point of the hood in the anteroposterior direction thereof.