There are provided a heat exchanger having a flat tube and a fin bonded together, without causing melting of a coating material covering the fin, and a method of manufacturing thereof. A heat exchanger includes: a flat tube having a flat cross-sectional shape and covered with an anticorrosive layer; and a fin bonded to the flat tube with a bonding agent on a first surface of the anticorrosive layer interposed therebetween, and covered with a coating material, the first surface of the anticorrosive layer having been roughened, and the bonding agent being fixed to the roughened first surface.