A combustion device, comprising: at least one burner having a flame outlet, wherein the at least one burner is for burning gas to generate flames through the flame outlet; a supporting assembly including a front cover, wherein the front cover has a flat cover plate which includes a plurality of holes passing between an exterior surface and an interior surface thereof, wherein the flat cover plate is rectangular; and an infrared ray generation mesh being disposed on the supporting assembly and corresponding to the flame outlet, the infrared ray generation mesh facing the interior surface of the cover plate, the infrared ray generation mesh being flame heated by the at least one burner to generate infrared rays passing through the holes; characterized in that the supporting assembly includes a rear cover; the infrared ray generation mesh is disposed between the front cover and the rear cover and faces the interior surface of the cover plate; wherein the front cover and the rear cover are metallic; wherein the front cover includes an upper side wall and two side walls; the upper side wall of the front cover is connected to a top edge of the cover plate and has a plurality of holes; the two side walls of the front cover are connected to two side edges of the cover plate; each of the two side walls of the front cover has a plurality of holes; wherein the cover plate has an opening located on an opposite side of the top edge and passing through the interior surface and the exterior surface of the cover plate; the flame outlet of the at least one burner is disposed below the opening; the flames generated through the flame outlet pass through the opening of the cover plate to heat the infrared ray generation mesh and pass through the plurality of holes of the cover plate to form open fire. at least one burner having a flame outlet, wherein the at least one burner is for burning gas to generate flames through the flame outlet; a supporting assembly including a front cover, wherein the front cover has a flat cover plate which includes a plurality of holes passing between an exterior surface and an interior surface thereof, wherein the flat cover plate is rectangular; and an infrared ray generation mesh being disposed on the supporting assembly and corresponding to the flame outlet, the infrared ray generation mesh facing the interior surface of the cover plate, the infrared ray generation mesh being flame heated by the at least one burner to generate infrared rays passing through the holes; characterized in that the supporting assembly includes a rear cover; the infrared ray generation mesh is disposed between the front cover and the rear cover and faces the interior surface of the cover plate; wherein the front cover and the rear cover are metallic; wherein the front cover includes an upper side wall and two side walls; the upper side wall of the front cover is connected to a top edge of the cover plate and has a plurality of holes; the two side walls of the front cover are connected to two side edges of the cover plate; each of the two side walls of the front cover has a plurality of holes; wherein the cover plate has an opening located on an opposite side of the top edge and passing through the interior surface and the exterior surface of the cover plate; the flame outlet of the at least one burner is disposed below the opening; the flames generated through the flame outlet pass through the opening of the cover plate to heat the infrared ray generation mesh and pass through the plurality of holes of the cover plate to form open fire.