To control film thickness and to form a coating film in a desired area.

In a thin film forming nozzle for forming a thin film of liquid spouted under prescribed pressure on a substrate, there are provided a liquid collecting part 2 to which liquid pressurized to a prescribed pressure is fed and a pair of spouting nozzles 3a, 3b arranged in the liquid collecting part 2 and for spouting the liquid fed to the liquid collecting part 2, and by making liquids spouted from the pair of the spouting nozzles 3a, 3b collide with each other, the spouted liquids and extended in a thin film to form a thin film on a substrate.