An air-conditioning apparatus comprising a heat exchanger and an outdoor fan supplying air to the heat exchanger, the heat exchanger, comprising: at least one heat exchanging unit including a plurality of stages of refrigerant flow passages each allowing refrigerant to flow in from an end portion on one side of each of the refrigerant flow passages, turn back at a first turn-back portion, and flow out of an end portion on an other side juxtaposed to the end portion on the one side; and a distributing and joining unit connected to the at least one heat exchanging unit, the distributing and joining unit including a distributing flow passage allowing the refrigerant to be distributed and flow into a plurality of the end portions on the one side, and a joining flow passage allowing the refrigerant to be joined and flow out of a plurality of the end portions on the other side, the distributing and joining unit separately including a first header including the distributing flow passage formed therein and excluding the joining flow passage, and a second header juxtaposed to the first header, the second header including the joining flow passage formed therein and excluding the distributing flow passage, the first header and the second header being juxtaposed to an one end of the at least one heat exchanging unit, characterized in that the second header is a stacking type header including a plurality of plate-like members (53, 54_1 to 54_3, 55, 56_1 to 56_4) including partial flow passages (53a, 54a_1 to 54a_3, 55a, 56a) formed therein and stacked to each other so that the partial flow passages (53a, 54a_1 to 54a_3, 55a, 56a) are communicated with each other to form the distributing flow passage or the joining flow passage, and the second header is arranged on a windward side of the air supplied by the outdoor fan with resect to the first header. at least one heat exchanging unit including a plurality of stages of refrigerant flow passages each allowing refrigerant to flow in from an end portion on one side of each of the refrigerant flow passages, turn back at a first turn-back portion, and flow out of an end portion on an other side juxtaposed to the end portion on the one side; and a distributing and joining unit connected to the at least one heat exchanging unit, the distributing and joining unit including a distributing flow passage allowing the refrigerant to be distributed and flow into a plurality of the end portions on the one side, and a joining flow passage allowing the refrigerant to be joined and flow out of a plurality of the end portions on the other side, the distributing and joining unit separately including a first header including the distributing flow passage formed therein and excluding the joining flow passage, and a second header juxtaposed to the first header, the second header including the joining flow passage formed therein and excluding the distributing flow passage, the first header and the second header being juxtaposed to an one end of the at least one heat exchanging unit, characterized in that the second header is a stacking type header including a plurality of plate-like members (53, 54_1 to 54_3, 55, 56_1 to 56_4) including partial flow passages (53a, 54a_1 to 54a_3, 55a, 56a) formed therein and stacked to each other so that the partial flow passages (53a, 54a_1 to 54a_3, 55a, 56a) are communicated with each other to form the distributing flow passage or the joining flow passage, and the second header is arranged on a windward side of the air supplied by the outdoor fan with resect to the first header.