To provide an air conditioner with high air-conditioning performance and superior quietness.

By forming a plurality of openings 6, 6, etc., on a circumferential wall 43 of a blowout side of a bell mouth 4 at predetermined intervals in its circumferential direction, a circulating flow is caused in a portion of the openings 6, an air current amount flowing to a side of a blowout grill 5 is reduced by only a flow rate of the circulating flow, and an unnecessary rise of fan hydrostatic pressure caused by the passing resistance of the blowout grill 5 is suppressed. By suppressing hydrostatic pressure in a rim of a blowout side of the bell mouth 4 by the circulating flow, the velocity distribution of a blowout air current to the side of the blowout grill is improved, and the unnecessary rise of the fan hydrostatic pressure is avoided. As a synergistic effect, an input of a fan motor is reduced, and the energy saving performance of the air conditioner is improved. By mutually deviating the openings 6, 6, etc., in an axial direction or a radial direction of the bell mouth 4, or in both directions, a periodic change of a sound pressure level in each opening 6, 6, etc., is reduced, a feeling of unpleasant noise is alleviated, and the low noise performance of the air conditioner is improved.