An ejector includes a first nozzle, a second nozzle, an atomization mechanism, and a mixer. A working fluid in a liquid phase is supplied to the first nozzle as a drive flow. A working fluid in a gas phase is sucked into the second nozzle. The atomization mechanism is disposed at an end of the first nozzle and atomizes the working fluid in a liquid phase while maintaining the liquid phase. The mixer generates a fluid mixture by mixing the atomized working fluid generated by the atomization mechanism and the working fluid in a gas phase sucked into the second nozzle. The atomization mechanism includes an ejection section that generates a jet of the working fluid in a liquid phase and a collision surface with which the jet from the ejection section collides. The collision surface is inclined with respect to a direction in which the jet flows.