A heat exchanger which reduces a flow loss of air and increases a heat exchange performance by preventing condensate water from staying at surfaces of fins. To this end, the heat exchanger includes: a plurality of tubes arranged with a predetermined interval so as to pass a fluid for the heat exchange; and fins mounted among the tubes for expanding a contact area with air, wherein the fins are tilted with a predetermined angle so as to prevent condensate water from staying at the surfaces of the fins.