PURPOSE: To prevent complicated intermittent operations of a compressor by sensing an operation period ending time of an indoor unit during an intemittent operation preferentially by a plurality of indoor unit controllers for individually controlling indoor units, and starting the operating period of its own indoor unit before the operating period ending time.

CONSTITUTION: An outdoor unit controller 8 for controlling an outdoor unit 10, and indoor unit controllers 9a-9c for controlling indoor units 1-3 are connected to a bus 20 to be able to communicate data, and the controllers 9a-9c individually control the operations of the units 1-3 based on an operation mode signal, a temperature signal and an operation signal. The controllers 9a-9c judge the operation signals of other units in a dehumidifying mode to check whether the other unit is intermittently operated or not, selects the unit lastly started to operate of all the units which are intermittently operated, and presumes its downtime. An operation starting time for starting the operation of own unit is calculated preferentially to the predetermined time from the presumed downtime, and its operating period is set.