In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, an insulation member is provided on an outer surface of the ejector to suppress a heat exchange with an external side. When a suction portion of the ejector is insulated by the insulation member, pressure loss in the suction portion can be reduced, a gas refrigerant ratio at an inlet port of the mixing portion can be reduced, and a liquid refrigerant amount to be supplied to the evaporator can be increased. In addition, when a mixing portion and a diffuser portion of the ejector are insulated, it can prevent liquid refrigerant from being excessively evaporated. As a result, it can effectively restrict heat loss due to a heat exchange in the ejector with the external side.