A heat exchange fin in a heat exchanger is disposed between two refrigerant pipes spaced apart from each other includes a guide protrusion including first inclined planes inclined upward along opposite sides of a center line of a refrigerant pipe row in a symmetric fashion and second inclined planes inclined downward from upper ends of the first inclined planes, and the first inclined planes and the second inclined planes are provided with louver members, thereby improving heat exchange efficiency.