A gas jetting apparatus comprising: a vessel unit; a gas supply unit for supplying a gas to said vessel unit; and a gas jetting cell unit provided in said vessel unit to jet the gas toward a treatment-target object, wherein said gas jetting cell unit includes: a first cone-shaped member; and a second cone-shaped member disposed to surround said first cone-shaped member in a side surface direction so that a gap (do) is formed with a side surface of said first cone-shaped member, an apex side of said first cone-shaped member and an apex side of said second cone-shaped member face said treatment-target object, such that the gas supplied from said gas supply unit enters from a bottom surface side of said first cone-shaped member and a bottom surface side of said second cone-shaped member into said gap (do), passes through said gap (do), and is jetted from the apex side of said first cone-shaped member and the apex side of said second cone-shaped member toward said treatment-target object, characterized in that said gas jetting cell unit further includes a jetting-out unit for jetting a gas toward said treatment-target object, an apex side of said first cone-shaped member and an apex side of said second cone-shaped member are coupled to a side surface side of said jetting-out unit, said jetting-out unit comprising a space unit formed internally, and a plurality of jetting-out holes coupled to said space unit, such that a gas supplied from said gas supply unit passes through said gap (do), is supplied to said space unit, and is jetted toward said treatment-target object via said plurality of jetting-out holes. a vessel unit; a gas supply unit for supplying a gas to said vessel unit; and a gas jetting cell unit provided in said vessel unit to jet the gas toward a treatment-target object, wherein said gas jetting cell unit includes: a first cone-shaped member; and a second cone-shaped member disposed to surround said first cone-shaped member in a side surface direction so that a gap (do) is formed with a side surface of said first cone-shaped member, a first cone-shaped member; and a second cone-shaped member disposed to surround said first cone-shaped member in a side surface direction so that a gap (do) is formed with a side surface of said first cone-shaped member, an apex side of said first cone-shaped member and an apex side of said second cone-shaped member face said treatment-target object, such that the gas supplied from said gas supply unit enters from a bottom surface side of said first cone-shaped member and a bottom surface side of said second cone-shaped member into said gap (do), passes through said gap (do), and is jetted from the apex side of said first cone-shaped member and the apex side of said second cone-shaped member toward said treatment-target object, characterized in that said gas jetting cell unit further includes a jetting-out unit for jetting a gas toward said treatment-target object, an apex side of said first cone-shaped member and an apex side of said second cone-shaped member are coupled to a side surface side of said jetting-out unit, said jetting-out unit comprising a space unit formed internally, and a plurality of jetting-out holes coupled to said space unit, such that a gas supplied from said gas supply unit passes through said gap (do), is supplied to said space unit, and is jetted toward said treatment-target object via said plurality of jetting-out holes.