An air-conditioning apparatus, comprising: a heat source side unit (1, 2) configured to heat or cool a heat medium used as a heat-conveying medium; an air handling side heat exchanger that exchanges heat between outside air that is sent into a building and the heat medium; and an indoor side heat exchanger that exchanges heat between indoor air and the heat medium, the heat source side unit (1, 2), the air handling side heat exchanger, and the indoor side heat exchanger being connected by piping to each other to form a heat medium cycle circuit through which the heat medium circulates, in the heat medium cycle circuit, a portion of the heat medium heated or cooled by the heat source side unit (1, 2) flowing into the indoor side heat exchanger after having passed through the air handling side heat exchanger, the heat medium cycle circuit being provided with an air handling side flow rate control device configured to adjust a flow rate of the heat medium that passes through the air handling side heat exchanger; characterized by the air-conditioning apparatus further comprising: an air handling unit housing that houses the air handling side flow rate control device, the air handling side heat exchanger, and an air handling unit control device configured to control the air handling side flow rate control device; and a heat source side unit control device (100, 200) configured to control an amount of heating or an amount of cooling that the heat source side unit (1, 2) supplies to the heat medium, wherein the air handling unit control device and the heat source side unit control device (100, 200) have a communication connection with each other. a heat source side unit (1, 2) configured to heat or cool a heat medium used as a heat-conveying medium; an air handling side heat exchanger that exchanges heat between outside air that is sent into a building and the heat medium; and an indoor side heat exchanger that exchanges heat between indoor air and the heat medium, the heat source side unit (1, 2), the air handling side heat exchanger, and the indoor side heat exchanger being connected by piping to each other to form a heat medium cycle circuit through which the heat medium circulates, in the heat medium cycle circuit, a portion of the heat medium heated or cooled by the heat source side unit (1, 2) flowing into the indoor side heat exchanger after having passed through the air handling side heat exchanger, the heat medium cycle circuit being provided with an air handling side flow rate control device configured to adjust a flow rate of the heat medium that passes through the air handling side heat exchanger; an air handling unit housing that houses the air handling side flow rate control device, the air handling side heat exchanger, and an air handling unit control device configured to control the air handling side flow rate control device; and a heat source side unit control device (100, 200) configured to control an amount of heating or an amount of cooling that the heat source side unit (1, 2) supplies to the heat medium, wherein the air handling unit control device and the heat source side unit control device (100, 200) have a communication connection with each other.