Disclosed is a heat exchanger including a plurality of tubes through which refrigerants flow, the tubes being spaced away from each other, and a plurality of fins through which the tubes are perpendicularly inserted, the fins being spaced away from each other at a predetermined distance, each of the fin having more than four peak portions and more than four valley portions that are alternately disposed. Heights or depths of at least two peak portions or at least two valley portions being different from each other.