The present invention has an object to provide an ejector cycle and an ejector, according to which a sufficient cooling performance can be obtained even when the input amount of the refrigerant to the ejector is decreased. A passage changeover means having a bypass channel is formed in an ejector. The passage changeover means opens the bypass channel in a bypass cooling operation, in which an input amount of the refrigerant to the ejector is decreased due to a low ambient temperature, and so on. Accordingly, in this bypass cooling operation, the refrigerant from an outside heat exchanger to the ejector bypasses an ejector nozzle and flows to an evaporator through the bypass channel.