PURPOSE: To reduce the irregularity of a divided stream region by miniaturizing a spray apparatus, in injecting a pressurized liquid from a single orifice nozzle to atomize the same through the impingement with a barrier body in a jet stream dividing region, by forming the cross-sectional area of the single orifice nozzle into a non-circular shape.

CONSTITUTION: A liquid is sent to a single orifice nozzle 1 having a nozzle orifice 2 under pressure by a pressurizing means 3. A jet stream is successively converted to a smooth stream, a vibrated stream and a divided stream and impinged to the barrier body provided to the downstream side of the nozzle 1 and atomized. In this apparatus, the nozzle orifice 2 of the single orifice nozzle 1 is formed into a non-circular shape. By this method, the length from the nozzle to a divided region is made short to enable the miniaturization of the spray apparatus, and to secure stable quality.