A gas blowoff nozzle includes: a casing including a gas blowoff face that blows off gas; a gas supply port provided to one end of the casing and supplying gas along the longitudinal direction of the nozzle; and a pressure equalizing chamber communicating with the gas supply port and the gas blowoff face, and including a partition plate including a plurality of tubular bodies having orifices on both ends. In each of the tubular bodies, an angle θ that a wall surface on a side closer to the gas supply port forms with the partition plate is 55° to 120° as an interior angle in a sectional shape of each of the tubular bodies. A gas circulation hole is provided on a face of each of the tubular bodies that comes into contact with the partition plate, the gas circulation hole passing through the face and the partition plate.