An air conditioner, comprising: an outdoor unit which has a compressor of a capacity variable type and an outdoor heat exchanger; a plurality of indoor units (Y1, Y2) which have an indoor heat exchanger (23, 33) and a flow regulating valve (22, 32); a first control means (27, 37) which is provided in each indoor unit and detects a difference between a room temperature and a set temperature as an air conditioning load for each indoor unit, the first control means informing the outdoor unit of a request capacity according to the air conditioning load; a second control means which is provided in the outdoor unit and controls the capacity of the compressor of the capacity variable type according to a sum of the request capacities of the indoor units; an operation means (28b, 38b) which each indoor unit has and which designates a capacity restriction mode; a third control means (27, 37) which is provided in each indoor unit and sets a maximum value to the request capacity according to an air conditioning load of the indoor unit when the capacity restriction mode is set by the operation means, characterized in that the air conditioner further comprises a valve aperture controller which is provided in the outdoor unit and calculates an aperture of the flow regulating valve (22, 32) of each indoor unit according to a cooling medium distribution ratio calculated on the basis of the request capacity from each indoor unit, wherein each of the indoor units can be operated so as to reach the set temperature without stopping decrease or increase of the room temperature notwithstanding the set maximum value to the request capacity. an outdoor unit which has a compressor of a capacity variable type and an outdoor heat exchanger; a plurality of indoor units (Y1, Y2) which have an indoor heat exchanger (23, 33) and a flow regulating valve (22, 32); a first control means (27, 37) which is provided in each indoor unit and detects a difference between a room temperature and a set temperature as an air conditioning load for each indoor unit, the first control means informing the outdoor unit of a request capacity according to the air conditioning load; a second control means which is provided in the outdoor unit and controls the capacity of the compressor of the capacity variable type according to a sum of the request capacities of the indoor units; an operation means (28b, 38b) which each indoor unit has and which designates a capacity restriction mode; a third control means (27, 37) which is provided in each indoor unit and sets a maximum value to the request capacity according to an air conditioning load of the indoor unit when the capacity restriction mode is set by the operation means, characterized in that the air conditioner further comprises a valve aperture controller which is provided in the outdoor unit and calculates an aperture of the flow regulating valve (22, 32) of each indoor unit according to a cooling medium distribution ratio calculated on the basis of the request capacity from each indoor unit, wherein each of the indoor units can be operated so as to reach the set temperature without stopping decrease or increase of the room temperature notwithstanding the set maximum value to the request capacity.