An air conditioner is provided and includes a louver which is provided at a blowing opening. The louver is moved rotationally from above to below or from below to above by a variable speed mechanism. At the time of heating, a louver rotational speed while the louver is moved rotationally in a range of a blowing angle .theta..sub.1 is set to a speed .omega..sub.1 within a vortices generation area relative to a wind velocity of blowing air flow. Also, a louver rotational speed while the louver is moved rotationally over the blowing angle .theta..sub.1 is set to a speed .omega..sub.1 within a vortices non-generation area relative to the wind velocity of blowing air flow. Thereby, at the time of heating, downward reach of warm air in a room while the louver is moved rotationally below the predetermined blowing angle and a temperature diffusibility while the louver is moved rotationally above the predetermined blowing angle are improved. Further, an air conditioner in which, at the time of cooling, a uniformity of temperature distribution is improved is also provided.