An air-conditioning apparatus including an indoor unit for disposing in a ceiling of a room comprising: a body casing of the indoor unit having a substantially rectangular parallelepiped shape, the body casing being formed with a body inlet port on a bottom side, being formed with a body outlet port on each of four lateral sides; a centrifugal fan provided inside the body casing; a fan motor for rotatably driving the centrifugal fan; an indoor heat exchanger provided inside the body casing, the indoor heat exchanger being disposed so as to substantially surround an outer periphery of the centrifugal fan in planar view; a joint provided in each body outlet port, the joints being protrudingly provided with a body-side duct connecting portion that is connected to a duct; and a plurality of outlet units each provided with an outlet-side duct connecting portion that is connected to the duct, each of the outlet units being connected to one of the body-side duct connecting portions through the duct and being formed with an outlet port on a bottom side thereof, characterized in that the bottom side of the body casing is not formed with the body outlet port, at least one of the joints is formed with a plurality of the body-side duct connecting portions, to each lateral side of the body casing at least one of the ducts can be connected through the joints and at least five ducts can be connected to the entirety of the body casing, each of the body outlet ports is opened in a rectangular shape, each of the body-side duct connecting portions has a round section, and each of the joints has a deformed portion that gradually deforms its shape from a rectangle into a circle from the connection portion with the body outlet port to the body-side duct connecting portion while reducing its cross-sectional area. a body casing of the indoor unit having a substantially rectangular parallelepiped shape, the body casing being formed with a body inlet port on a bottom side, being formed with a body outlet port on each of four lateral sides; a centrifugal fan provided inside the body casing; a fan motor for rotatably driving the centrifugal fan; an indoor heat exchanger provided inside the body casing, the indoor heat exchanger being disposed so as to substantially surround an outer periphery of the centrifugal fan in planar view; a joint provided in each body outlet port, the joints being protrudingly provided with a body-side duct connecting portion that is connected to a duct; and a plurality of outlet units each provided with an outlet-side duct connecting portion that is connected to the duct, each of the outlet units being connected to one of the body-side duct connecting portions through the duct and being formed with an outlet port on a bottom side thereof, characterized in that the bottom side of the body casing is not formed with the body outlet port, at least one of the joints is formed with a plurality of the body-side duct connecting portions, to each lateral side of the body casing at least one of the ducts can be connected through the joints and at least five ducts can be connected to the entirety of the body casing, each of the body outlet ports is opened in a rectangular shape, each of the body-side duct connecting portions has a round section, and each of the joints has a deformed portion that gradually deforms its shape from a rectangle into a circle from the connection portion with the body outlet port to the body-side duct connecting portion while reducing its cross-sectional area.