An air conditioner indoor unit capable of changing the direction of conditioned air blown out from an outlet port of said air conditioning unit to a predetermined direction, provided with: a wind direction adjusting blade, for changing the blowout angle of the conditioned air in relation to a horizontal plane; and a control portion, through which wind direction automatic control for automatically changing the direction of the conditioned air via the wind direction adjustment blade can be selectively set, wherein the wind direction automatic control includes at least an upper airflow mode for controlling the direction of the conditioned air to be horizontal or upward, and an upward and downward wind direction mode for applying conditioned air to a person while causing the wind direction of the conditioned air to change upwardly and downwardly, and the control portion, when the wind direction automatic control is selected for the cooling operation, is for implementing the upper airflow mode in the state in which the room temperature is not in a stable region, and is for implementing the upward and downward wind direction mode in the state in which the room temperature is in the stable region, wherein the stable region is within a target temperature range based on temperatures as set, characterized in that the air conditioner indoor unit is further provided with a Coanda blade provided in the vicinity of the outlet port, for forming the conditioned air into a Coanda airflow caused to follow the lower face of the blade itself, guided in a predetermined direction, wherein, in the upper airflow mode, the Coanda blade is configured to form the conditioned air into an upwardly directed Coanda airflow, and in the upward and downward wind direction mode, said air conditioner indoor unit is configured to generate fluctuating airflow by mixing a plurality of patterns of wind direction change and while generating fluctuating airflow the air conditioner indoor unit is further configured to mix timeslots for generating the Coanda airflow and timeslots for not generating the Coanda airflow. a wind direction adjusting blade, for changing the blowout angle of the conditioned air in relation to a horizontal plane; and a control portion, through which wind direction automatic control for automatically changing the direction of the conditioned air via the wind direction adjustment blade can be selectively set, wherein the wind direction automatic control includes at least an upper airflow mode for controlling the direction of the conditioned air to be horizontal or upward, and an upward and downward wind direction mode for applying conditioned air to a person while causing the wind direction of the conditioned air to change upwardly and downwardly, and the control portion, when the wind direction automatic control is selected for the cooling operation, is for implementing the upper airflow mode in the state in which the room temperature is not in a stable region, and is for implementing the upward and downward wind direction mode in the state in which the room temperature is in the stable region, wherein the stable region is within a target temperature range based on temperatures as set, characterized in that the air conditioner indoor unit is further provided with a Coanda blade provided in the vicinity of the outlet port, for forming the conditioned air into a Coanda airflow caused to follow the lower face of the blade itself, guided in a predetermined direction, wherein, in the upper airflow mode, the Coanda blade is configured to form the conditioned air into an upwardly directed Coanda airflow, and in the upward and downward wind direction mode, said air conditioner indoor unit is configured to generate fluctuating airflow by mixing a plurality of patterns of wind direction change and while generating fluctuating airflow the air conditioner indoor unit is further configured to mix timeslots for generating the Coanda airflow and timeslots for not generating the Coanda airflow.