An air conditioner configured to communicate with a portable terminal including an air pressure measurement unit, the air pressure measurement unit being configured to measure an air pressure value, the air conditioner comprising: an air conditioning unit whose wind direction and airflow volume are changeable; an air conditioning communication unit configured to receive an air pressure value from the portable terminal by communicating with the portable terminal; a wind velocity calculation unit configured to calculate a wind velocity of wind received by the portable terminal from a variation in a plurality of air pressure values received by the air conditioning communication unit, and to specify a presence direction that is a direction in which the portable terminal is present with respect to the air conditioner; an air conditioning control determination unit configured to determine a wind direction and an airflow volume of the air conditioning unit in accordance with the wind velocity and the presence direction; and an air conditioning control unit configured to control the air conditioning unit so that the determined wind direction and airflow volume are obtained; wherein the wind velocity calculation unit specifies the variation by using a target difference that is a difference between a first air pressure value and a smallest value in a plurality of second air pressure values, the first air pressure value being measured by the air pressure measurement unit with a current wind direction and a current airflow volume of the air conditioning unit, the plurality of second air pressure values being measured a plurality of times by the air pressure measurement unit with a wind direction of the air conditioning unit being changed in a horizontal direction by the air conditioning control unit; and wherein the portable terminal is present in a direction of a set value of a wind direction corresponding to a maximum value of the air pressure values. an air conditioning unit whose wind direction and airflow volume are changeable; an air conditioning communication unit configured to receive an air pressure value from the portable terminal by communicating with the portable terminal; a wind velocity calculation unit configured to calculate a wind velocity of wind received by the portable terminal from a variation in a plurality of air pressure values received by the air conditioning communication unit, and to specify a presence direction that is a direction in which the portable terminal is present with respect to the air conditioner; an air conditioning control determination unit configured to determine a wind direction and an airflow volume of the air conditioning unit in accordance with the wind velocity and the presence direction; and an air conditioning control unit configured to control the air conditioning unit so that the determined wind direction and airflow volume are obtained; wherein the wind velocity calculation unit specifies the variation by using a target difference that is a difference between a first air pressure value and a smallest value in a plurality of second air pressure values, the first air pressure value being measured by the air pressure measurement unit with a current wind direction and a current airflow volume of the air conditioning unit, the plurality of second air pressure values being measured a plurality of times by the air pressure measurement unit with a wind direction of the air conditioning unit being changed in a horizontal direction by the air conditioning control unit; and wherein the portable terminal is present in a direction of a set value of a wind direction corresponding to a maximum value of the air pressure values.