A heat exchanger includes a plurality of heat exchange tubes and corrugated fins. The heat exchange tubes are spaced apart from one another in a vertical direction of the heat exchanger. The corrugated fins are each disposed between adjacent heat exchange tubes. Each of the corrugated fins includes crest portions, trough portions, and connection portions. The crest portions extend in an air passage direction of the heat exchanger. The trough portions extend in the air passage direction. The connection portions connect the crest portions and the trough portions. The number of the crest portions of each of the corrugated fins disposed between adjacent heat exchange tubes falls within a range of a designed number ±2. The designed number is a standard number.