a fluid dispersal device has a fluid inlet port , a nozzle , a fluid jet passage and an outlet throat provided in a housing and arranged from the upstream side thereof in order . the sidewalls defining the fluid jet passage are composed of deflection walls , turn walls and branch walls arranged in order from the upstream side thereof . the deflection walls are parallel walls symmetric with respect to the center line of said nozzle , each of the turn walls continues from the downstream end of each of the deflection walls and is formed into a rectangular concave wall , the distance between the opposed rectangular concave walls is larger than that between the deflection walls . the branch walls continue from the downstream ends of the turn walls and project in opposite directions . the outlet throat is defined by the oppositely projecting branch walls . the fluid jet jetted from the nozzle is rightward of leftward deflected due to the interaction between the fluid jet and the deflection walls . the deflection fluid jet is branched by the branch walls into two branch flows in accordance with the amount of deflection thereof . one branch flow is dispersed from the outlet throat while the other branch flow flows into one of the turn walls . the turn walls turn the branch flows and make them collide with the deflected fluid jet perpendicularly to push the deflected fluid jet in a direction opposite to the deflecting direction thereof . thus , the fluid jet is periodically deflected and oscillated within the fluid jet passage and is dispersed from the outlet throat .