To provide a ceiling-embedded type air conditioner capable of suppressing increase in its vertical dimension and blowing out fresh air to the inside of an air conditioned room even when the air conditioner is not operated by providing an outside air introduction device capable of introducing outside air all the time even when the air conditioner is not operated.

The air conditioner includes: a body 1 having an air suction part 2 located at the center in the lower part, an air blowout part 3 located on the outer periphery of the air suction part 2, and an air blower 4 and a heat exchanger 5 which are located in an air passage connecting the air suction part 2 to the air blowout part 3; and a decorative panel 8 comprising a suction port 6 corresponding to the air suction part 2 and a blowout port 7 corresponding to the air blowout part 3. An outside air taking-in device 11 including an outside air introducing port 9 in one side part and an outside air delivery port 10 adjacent to the blowout port 7 in the lower part is provided in the lateral part of the body 1, and an auxiliary panel including an outside air blowout port 12 communicated with the outside air delivery port 10 is provided on the outer periphery of the decorative panel 8.