HEAT EXCHANGER

A heat exchanger includes a heat exchanging portion, a reservoir that performs gas-liquid separation on a gas-liquid two-phase refrigerant that flows out from the heat exchanging portion into a gas-phase refrigerant and a liquid-phase refrigerant and stores the liquid-phase refrigerant, and an inflow passage that allows the gas-liquid two-phase refrigerant flowing out from the heat exchanging portion to flow into the reservoir. The inflow passage is connected so as to be in communication with an inlet port of the reservoir which is disposed above a liquid surface of the liquid-phase refrigerant stored in the reservoir.