An air conditioner (10) includes a refrigerant circuit (20) including a plurality of indoor heat exchangers (27). A controller (1) for controlling operation of the air conditioner (10) includes a change unit (5) configured to change a set temperature Tem to a value larger than a current value when the minimum target superheat degree SHsm of target superheat degrees SHs determined for the respective indoor heat exchangers (27) is higher than a predetermined value SHt.