An ejector includes a swirl flow channel that is arranged on an upstream side of a nozzle portion. The swirl flow channel swirls the high pressure refrigerant and allows the refrigerant in a state of a gas-liquid mixed phase to flow into the nozzle portion. The ejector further includes a flow-rate changeable mechanism that is disposed at the upstream side of the swirl flow channel, and is capable of changing a flow rate of the high pressure refrigerant that flows into the swirl flow channel. Accordingly, a nozzle efficiency can be improved, and an operation according to a load of the refrigeration cycle is possible.