A heat exchanger (100, 101, 102) comprising: a plurality of first heat transfer tubes disposed at intervals in a first direction and having respective first ends and respective second ends; a plurality of second heat transfer tubes disposed at a distance from the plurality of first heat transfer tubes to face the plurality of first heat transfer tubes in a second direction crossing the first direction, located on leeward side relative to the plurality of first heat transfer tubes, and having respective third ends and respective fourth ends; a plurality of fins connecting the first heat transfer tubes adjacent to each other and connecting the second heat transfer tubes adjacent to each other; a first distribution unit connecting the first ends of the plurality of first heat transfer tubes and the third ends of the plurality of second heat transfer tubes; and a second distribution unit (24, 25, 26) connecting the second ends of the plurality of first heat transfer tubes and the fourth ends of the plurality of second heat transfer tubes, the first distribution unit including a flow rate control unit (2, 9, 10) configured to switch between a first state and a second state, in the first state, refrigerant flowing in the plurality of first heat transfer tubes and the plurality of second heat transfer tubes, and in the second state, the flow rate of the refrigerant of the plurality of second heat transfer tubes is not less than in the first state, in only the plurality of first heat transfer tubes, a flow rate of the refrigerant being smaller than a flow rate of the refrigerant in the first state; each of the plurality of second heat transfer tubes includes a first side end and a second side end, the first side end of each second heat transfer tube is located outside in the second direction, the second side end of each second heat transfer tube is located opposite to the first side end in the second direction, the second side end of each second heat transfer tube is facing the first heat transfer tube with a distance therebetween, characterized in that the second side end of each second heat transfer tube is provided to be located on windward side of fins relative to the center of fins in the second direction. a plurality of first heat transfer tubes disposed at intervals in a first direction and having respective first ends and respective second ends; a plurality of second heat transfer tubes disposed at a distance from the plurality of first heat transfer tubes to face the plurality of first heat transfer tubes in a second direction crossing the first direction, located on leeward side relative to the plurality of first heat transfer tubes, and having respective third ends and respective fourth ends; a plurality of fins connecting the first heat transfer tubes adjacent to each other and connecting the second heat transfer tubes adjacent to each other; a first distribution unit connecting the first ends of the plurality of first heat transfer tubes and the third ends of the plurality of second heat transfer tubes; and a second distribution unit (24, 25, 26) connecting the second ends of the plurality of first heat transfer tubes and the fourth ends of the plurality of second heat transfer tubes, the first distribution unit including a flow rate control unit (2, 9, 10) configured to switch between a first state and a second state, in the first state, refrigerant flowing in the plurality of first heat transfer tubes and the plurality of second heat transfer tubes, and in the second state, the flow rate of the refrigerant of the plurality of second heat transfer tubes is not less than in the first state, in only the plurality of first heat transfer tubes, a flow rate of the refrigerant being smaller than a flow rate of the refrigerant in the first state; each of the plurality of second heat transfer tubes includes a first side end and a second side end, the first side end of each second heat transfer tube is located outside in the second direction, the second side end of each second heat transfer tube is located opposite to the first side end in the second direction, the second side end of each second heat transfer tube is facing the first heat transfer tube with a distance therebetween, characterized in that the second side end of each second heat transfer tube is provided to be located on windward side of fins relative to the center of fins in the second direction.