An air conditioning indoor unit comprising: a casing configured for being attached to a wall surface facing an air conditioning target space, the casing including a blow-out port; a fan disposed in the casing and configured to send air to the blow-out port; a first horizontal blade configured to adjust an up-and-down wind direction of blow-out air flowing from the blow-out port to the air conditioning target space; a first drive unit configured to drive the first horizontal blade; a second horizontal blade disposed on a side of the wall surface of the first horizontal blade and configured to adjust the up-and-down wind direction of the blow-out air; a second drive unit configured to drive the second horizontal blade; and a control device (100, 200) configured to control the fan and the first and second drive units (73, 74), wherein the air conditioning indoor unit is capable of performing a heating operation in a first airflow control mode in which a distance between the first horizontal blade and the second horizontal blade is wider on a downstream side of a flow of the blow-out air than on an upstream side of the flow of the blow-out air, the blow-out air flows diagonally downward on an opposite side of the wall surface side, part of the blow-out air flows along a lower wing surface of the first horizontal blade, and another part of the blow-out air flows along an upper wing surface (5 1c) of the second horizontal blade, and in a third airflow control mode in which the blow-out air flows on the wall surface side more than in the first airflow control mode, in the third airflow control mode, the blow-out air flowing downward along the wall surface, characterized in that: the air conditioning indoor unit is capable of performing a heating operation in a second airflow control mode in which the blow-out air flows along a horizontal direction, the control device (100, 200) is configured to switch the second airflow control mode, the first airflow control mode, and the third airflow control mode in this order after the heating operation starts, the air conditioning indoor unit further comprises an indoor temperature sensor configured to detect an indoor temperature, and in the third airflow control mode, at least when the indoor temperature detected by the indoor temperature sensor becomes equal to or lower than a third predetermined temperature, the control device (100, 200) is configured to switch the third airflow control mode to the first airflow control mode. a casing configured for being attached to a wall surface facing an air conditioning target space, the casing including a blow-out port; a fan disposed in the casing and configured to send air to the blow-out port; a first horizontal blade configured to adjust an up-and-down wind direction of blow-out air flowing from the blow-out port to the air conditioning target space; a first drive unit configured to drive the first horizontal blade; a second horizontal blade disposed on a side of the wall surface of the first horizontal blade and configured to adjust the up-and-down wind direction of the blow-out air; a second drive unit configured to drive the second horizontal blade; and a control device (100, 200) configured to control the fan and the first and second drive units (73, 74), wherein the air conditioning indoor unit is capable of performing a heating operation in a first airflow control mode in which a distance between the first horizontal blade and the second horizontal blade is wider on a downstream side of a flow of the blow-out air than on an upstream side of the flow of the blow-out air, the blow-out air flows diagonally downward on an opposite side of the wall surface side, part of the blow-out air flows along a lower wing surface of the first horizontal blade, and another part of the blow-out air flows along an upper wing surface (5 1c) of the second horizontal blade, and in a third airflow control mode in which the blow-out air flows on the wall surface side more than in the first airflow control mode, in the third airflow control mode, the blow-out air flowing downward along the wall surface, the air conditioning indoor unit is capable of performing a heating operation in a second airflow control mode in which the blow-out air flows along a horizontal direction, the control device (100, 200) is configured to switch the second airflow control mode, the first airflow control mode, and the third airflow control mode in this order after the heating operation starts, the air conditioning indoor unit further comprises an indoor temperature sensor configured to detect an indoor temperature, and in the third airflow control mode, at least when the indoor temperature detected by the indoor temperature sensor becomes equal to or lower than a third predetermined temperature, the control device (100, 200) is configured to switch the third airflow control mode to the first airflow control mode.