A method of controlling a ceiling type air conditioner including a panel located on a ceiling surface, outlets formed at positions corresponding to four sides of the panel, a first vane group for opening and closing the outlets located at two opposing sides, and a second vane group for opening and closing the outlets located at the other two opposing sides includes performing a dynamic airflow mode in which an indoor temperature reaches a set temperature by controlling rotation angles of the first vane group and the second vane group, and calculating a pleasant airflow index Y for determining a pleasant feeling of a user at the set temperature. The pleasant airflow index is calculated using the indoor temperature, the rotation angle of the first vane group or the second vane group, an air volume, a distance from a floor surface and an airflow position as variables.