An operation terminal to make settings to a plurality of indoor units installed in a room in order to condition air in the room, comprising: a display unit with a display screen configured to display an airflow input screen image indicating a plurality of icons (173d, 173e and 173f) corresponding to the plurality of indoor units and a layout of the room; an input unit configured to receive input of a trace indicating an airflow on the display screen displaying the airflow input screen image; the trace is a drag performed by the user with a finger from at least one of the icons (173d, 173e and 173f) towards a direction of making air flow so that the trace becomes longer with the increase in the air volume; a terminal side control unit; a terminal-side storage unit configured to store information necessary for processes in the operation terminal; and a terminal-side communication unit configured to transmit a first command for setting an air direction and air volume corresponding to the trace on at least one of the plurality of indoor units; the terminal side control unit is configured to determine, when a straight line is inputted as a trace indicating an airflow, the direction from the starting point to the endpoint of the straight line as the horizontal air direction of one indoor unit which corresponds to one icon and is included in the plurality of indoor units and is configured to determine the air volume of the one indoor unit so that the air volume from the one indoor unit increases with the increase in the length of the straight line, and generates a command for setting the determined air direction and the determined air volume to the one indoor unit. a display unit with a display screen configured to display an airflow input screen image indicating a plurality of icons (173d, 173e and 173f) corresponding to the plurality of indoor units and a layout of the room; an input unit configured to receive input of a trace indicating an airflow on the display screen displaying the airflow input screen image; the trace is a drag performed by the user with a finger from at least one of the icons (173d, 173e and 173f) towards a direction of making air flow so that the trace becomes longer with the increase in the air volume; a terminal side control unit; a terminal-side storage unit configured to store information necessary for processes in the operation terminal; and a terminal-side communication unit configured to transmit a first command for setting an air direction and air volume corresponding to the trace on at least one of the plurality of indoor units; the terminal side control unit is configured to determine, when a straight line is inputted as a trace indicating an airflow, the direction from the starting point to the endpoint of the straight line as the horizontal air direction of one indoor unit which corresponds to one icon and is included in the plurality of indoor units and is configured to determine the air volume of the one indoor unit so that the air volume from the one indoor unit increases with the increase in the length of the straight line, and generates a command for setting the determined air direction and the determined air volume to the one indoor unit.