A heat exchanger may include flat tubes formed of a microchannel type, and first and second fins positioned at a top and bottom of the flat tubes so as to conduct the heat of the flat tubes. The first and second fins may be respectively provided with first and second condensate water discharge fins at a top and bottom. The second condensate water discharge fins of the first fins and the first condensate water discharge fins of the second fins may come into contact, and the second condensate water discharge fins of the first fins and the first condensate water discharge fins of the second fins may be disposed in a line with respect to a vertical direction, thereby having an advantage of quickly transferring condensate water formed at the top to the bottom.