In a mist nozzle, a liquid stored in a liquid storage tank is pressurized by a liquid supplier and is supplied to the mist nozzle, so that a liquid flow is introduced from an upstream of a gas-liquid mixing section and a vicinity of a wall surface of the gas-liquid mixing section into the gas-liquid mixing section on an outer lid side. A pressurized gas is supplied from a gas supplier from a facing surface, so that a gas flow introduces into the gas-liquid mixing section and collides with the liquid flow, and a gas-liquid mixed flow is advanced to a spout portion while circulating the wall surface of the gas-liquid mixing section on the outer lid side. Therefore, it is possible to promote atomization of the liquid in the gas-liquid mixing section and spray a liquid having a smaller particle diameter.