An ion exchanger includes a case and an ion exchange resin. The case includes an inflow hole into which a refrigerant flows and an outflow hole out of which the refrigerant flows. The ion exchange resin is arranged in the case to remove ions from the refrigerant. The inflow hole and the outflow hole are located at a lower end of the case. The case accommodates a tube extending in a vertical direction and connecting to the outflow hole. The ion exchange resin is located between an inner wall of the case and an outer wall of the tube. The inflow hole is formed so that the refrigerant flows through the inflow hole into the case and evenly into the ion exchange resin from a lower end surface of the ion exchange resin.