A heat exchanger includes: a plurality of flat tubes arranged in a height direction of the heat exchanger; a connection portion in which a plurality of connection spaces are provided as spaces with which ends of the plurality of flat tubes are connected; and a refrigerant distributor connected to each of the plurality of connection spaces. The flat tubes each have a first side end portion located on a windward side, a second side end portion located on a leeward side, and a plurality of refrigerant passages arranged between the first and second side end portions. Each flat tube is inclined such that in the height direction, the position of the first side end portion is lower than the position of the second side end portion. The connection spaces are spaced from each other in the height direction, and a lower side of each of the connection spaces has a first region located on the windward side and a second region located on the leeward side, and is inclined such that in the height direction, the position of the first region is lower than a position of the second region.