A heat exchanger of the present disclosure is operated in a cooling operation mode in which a region to be heat-exchanged is cooled by the heat exchanger or in a drying operation mode in which the heat exchanger is supplied with wind from a blowing fan, and comprises: a refrigerant pipe which forms a flow path of a refrigerant; a cooling fin which is coupled to the refrigerant pipe; and a hydrophilic coating with which the surface of at least one of the refrigerant pipe and the cooling fin is coated, wherein the hydrophilic coating contains: a first type transition metal oxide which becomes acidic by reacting with water formed on the refrigerant pipe or the cooling fin, so as to have antimicrobial activity when the heat exchanger is operated in the cooling operation mode; and a second type transition metal oxide or a post transition metal oxide which has antimicrobial activity when the heat exchanger is operated in the drying operation mode.