To provide an inexpensive heat exchanger for hot water supply which exhibits high heat efficiency and prevents a refrigerant from being mixed in water supply.

The heat exchanger 7 for hot water supply includes a refrigerant pipe 72, in which a refrigerant for heating flows, and which is arranged in a water flow passage 71 for distributing water to be heated for hot water supply. Material used for an outer surface of the refrigerant pipe 72 exhibits higher corrosion resistance than that of an inner surface of the water flow passage 71, and the water flow passage 71 and the refrigerant pipe 72 are formed of copper or copper alloy. A plated layer 73 is formed on the outer surface of the refrigerant pipe 72, and the corrosion resistance of the outer surface of the refrigerant pipe 72 is increased than that of the water flow passage 71.