An ejector includes an atomization mechanism arranged at an end of a first nozzle. The atomization mechanism includes a plurality of orifices and a collision plate against which each of a plurality of jets ejected from the plurality of orifices collides. The collision plate includes a first principal surface and a second principal surface as a collision surface against which the jet collides, each of the first principal surface and the second principal surface extending toward an outlet of the ejector. The plurality of orifices includes a plurality of first orifices arranged on a side of the first principal surface of the collision plate and a plurality of second orifices arranged on a side of the second principal surface of the collision plate.