To provide a heat exchanger having an improved durability and heat- exchange effectiveness by blocking out contact with a corrosive environment, such as a plating bath, a semiconductor-manufacturing line, a mixed liquor of hydrochloric acid or an organic solvent.

A heat-exchanger tube 11 is covered with a corrosion-resistant thermoplastic resin. A metal hollow core-tube 111 of the tube 11 is jointed to a hollow head 12 in a manner of being capable of communication. The hollow head 12 is covered with a heat-shrinkable tube 122 made of a corrosion-resistant thermoplastic resin. A joint 13 made of a corrosion-resistant thermoplastic resin is mounted to the joint part of the core tube and the hollow head. The covered part of the heat-exchanger tube and the heat-shrinkable tube of the hollow head are jointed through the joint 13, thus the heat exchanger is blocked out contact with the corrosive environment.