The spray gun is provided with a nozzle section which mixes gas into raw material liquid and also ejects the raw material liquid. The internal space of the nozzle section has an introduction path into which the raw material liquid is introduced, an open portion in which a flow path is enlarged more than the introduction path, thereby ejecting the raw material liquid in a fine particle form, a reduced diameter portion in which a flow path is made narrower than the open portion, thereby re-aggregating the raw material liquid in a fine particle form, and an ejection orifice portion which ejects the raw material liquid to the outside. In the nozzle section, a gas introduction hole which introduces gas into a base-end-side portion of the open portion is formed.