An air conditioner comprising: an outdoor unit; a plurality of indoor units (5a, 5b, 5c) each of which includes an indoor heat exchanger (51a, 51b, 51c) and an indoor expansion valve (52a, 52b, 52c); an superheating degree detector which detects a refrigerant superheating degree which is a superheating degree of a refrigerant flowing out from each indoor heat exchanger (51a, 51b, 51c) when each indoor heat exchanger (51a, 51b, 51c) is functioning as an evaporator; and a controller (200, 500a, 500b, 500c) which is configured to adjust degrees of opening of the plurality of indoor expansion valves (52a, 52b, 52c), wherein the controller (200, 500a, 500b, 500c) is configured to execute a refrigerant amount balance control to adjust the degree of opening of each indoor expansion valve (52a, 52b, 52c) such that an average refrigerant superheating degree (SHv) is obtained by averaging a maximum value (SHmax) and a minimum value (SHmin) of the refrigerant superheating degrees detected by the superheating degree detector, and the refrigerant superheating degree of each indoor unit (5a, 5b, 5c) becomes the average refrigerant superheating degree (SHv), characterized in that the controller (200, 500a, 500b, 500c) is configured to obtain a refrigerant superheating degree difference (SHd) which is a difference between the maximum value (SHmax) and the minimum value (SHmin) of the refrigerant superheating degrees of the indoor units (5a, 5b, 5c), if the obtained refrigerant superheating degree difference (SHd) is greater than a predetermined threshold superheating degree difference (SHTs), the controller is configured to determine whether there is an indoor unit (5a, 5b, 5c) where cooling ability required by the plurality of indoor units (5a, 5b, 5c) is displayed or not, and when there is an indoor unit (5a, 5b, 5c) where the required cooling ability cannot be displayed, the controller (200, 500a, 500b, 500c) is configured to execute the refrigerant amount balance control. an outdoor unit; a plurality of indoor units (5a, 5b, 5c) each of which includes an indoor heat exchanger (51a, 51b, 51c) and an indoor expansion valve (52a, 52b, 52c); an superheating degree detector which detects a refrigerant superheating degree which is a superheating degree of a refrigerant flowing out from each indoor heat exchanger (51a, 51b, 51c) when each indoor heat exchanger (51a, 51b, 51c) is functioning as an evaporator; and a controller (200, 500a, 500b, 500c) which is configured to adjust degrees of opening of the plurality of indoor expansion valves (52a, 52b, 52c), wherein the controller (200, 500a, 500b, 500c) is configured to execute a refrigerant amount balance control to adjust the degree of opening of each indoor expansion valve (52a, 52b, 52c) such that an average refrigerant superheating degree (SHv) is obtained by averaging a maximum value (SHmax) and a minimum value (SHmin) of the refrigerant superheating degrees detected by the superheating degree detector, and the refrigerant superheating degree of each indoor unit (5a, 5b, 5c) becomes the average refrigerant superheating degree (SHv), characterized in that the controller (200, 500a, 500b, 500c) is configured to obtain a refrigerant superheating degree difference (SHd) which is a difference between the maximum value (SHmax) and the minimum value (SHmin) of the refrigerant superheating degrees of the indoor units (5a, 5b, 5c), if the obtained refrigerant superheating degree difference (SHd) is greater than a predetermined threshold superheating degree difference (SHTs), the controller is configured to determine whether there is an indoor unit (5a, 5b, 5c) where cooling ability required by the plurality of indoor units (5a, 5b, 5c) is displayed or not, and when there is an indoor unit (5a, 5b, 5c) where the required cooling ability cannot be displayed, the controller (200, 500a, 500b, 500c) is configured to execute the refrigerant amount balance control.