PURPOSE: To raise cooling efficiency by enabling the alternate operation of indoor units when the temperature of the outdoor air is higher than the setpoint and the simultaneous operation when the temperature of the outdoor air is lower than that through a thermostat provided in an outdoor unit of a multi-type cooler.

CONSTITUTION: When the temperature of the outdoor air is higher than the setpoint, a thermostat 6 in an outdoor unit 1 thrns to be ON. When the indoor units in both chambers A and B are operated, relays 10 and 11 close contacts 10a and 11a to energize a timer relay 7, change over a change-over contact 7a between a-b and a-c every set time, energize relays 8 and 9 alternately to open contacts 8a and 9a alternately, open the closed solenoid valve of either 13 or 12, energize a relay 5 or 4 to close contact 5a or 4a of a compressor 2, thus operating the indoor unit altenately. When the temperature of the outdoor air is lower than the setpoint, a thermostat 6 opens and contacts 8a and 9a are closed, thus both indoor units are operated simultaneously.