A hood ventilation apparatus comprising: (a) a hood including a main body installed above a cooking source and having a suction opening at a lower surface thereof into which air containing cooking by-products is sucked, and an exhaust duct extending to an upper side of the main body and exhausting the sucked air; (b) a first blower mounted in the exhaust duct, for generating a suction force to suck air into the hood; (c) a walljet guiding member (430, 431, 432) installed at an outer circumference of the main body, for allowing air from the inside of the hood to flow along the surface of the walljet guiding member; (d) a second blower provided in the main body, for supplying air to the walljet guiding member; and (e) a walljet guiding frame installed in the main body so as to cover the second blower except for the opened one side of the main body at which the walljet guiding member is installed; (f) wherein one lateral surface of the main body is opened, an air guiding plate is installed at one end of an upper casing of the main body at the opened one side of the main body, the walljet guiding member (430, 431, 432) is fixedly installed between the air guiding plate and one end of a lower casing of the main body, and a walljet passage is formed between the air guiding plate and a surface of the walljet guiding member (430, 431, 432); characterized in that the air guiding plate has a constant radius of curvature along the surface of the walljet guiding member or a curved middle guiding plate (412, 413, 414) is further positioned between the air guiding plate and the walljet guiding member (430, 431, 432). (a) a hood including a main body installed above a cooking source and having a suction opening at a lower surface thereof into which air containing cooking by-products is sucked, and an exhaust duct extending to an upper side of the main body and exhausting the sucked air; (b) a first blower mounted in the exhaust duct, for generating a suction force to suck air into the hood; (c) a walljet guiding member (430, 431, 432) installed at an outer circumference of the main body, for allowing air from the inside of the hood to flow along the surface of the walljet guiding member; (d) a second blower provided in the main body, for supplying air to the walljet guiding member; and (e) a walljet guiding frame installed in the main body so as to cover the second blower except for the opened one side of the main body at which the walljet guiding member is installed; (f) wherein one lateral surface of the main body is opened, an air guiding plate is installed at one end of an upper casing of the main body at the opened one side of the main body, the walljet guiding member (430, 431, 432) is fixedly installed between the air guiding plate and one end of a lower casing of the main body, and a walljet passage is formed between the air guiding plate and a surface of the walljet guiding member (430, 431, 432); characterized in that the air guiding plate has a constant radius of curvature along the surface of the walljet guiding member or a curved middle guiding plate (412, 413, 414) is further positioned between the air guiding plate and the walljet guiding member (430, 431, 432). the air guiding plate has a constant radius of curvature along the surface of the walljet guiding member or a curved middle guiding plate (412, 413, 414) is further positioned between the air guiding plate and the walljet guiding member (430, 431, 432).