Abstract: Disclosed is a heat exchanger wherein an antibacterial member can be installed at a low cost and without using a dedicated fixing member, a drop in heat exchange efficiency due to the installation of the antibacterial member is prevented, and which can maintain high design flexibility. The disclosed heat exchanger is provided with a heat radiating member comprising at least a plurality of tubes which are arranged in a planar manner and through which a heat exchange medium flows, and the heat exchanger is characterized by being constructed such that a water absorption sheet substrate for holding antibacterial components is partially attached to the heat radiating member, and the antibacterial components can disperse, following the surface of the radiating member, via water components which have been absorbed by the water absorption sheet substrate.