To provide an air conditioner capable of automatically cleaning a filter for inhibiting the suction of dust.

Air sucked into an air conditioner 30 by a suction port 31 by rotation of an air blower 23 is stripped of dust by a filter 32 so that the dust is not sucked into the air conditioner 30. The dust thus removed sticks to the filter 32 on a part located opposite to the suction port 31. If a specified integrated time is reached in the operation of the air conditioner 30, a shaft 42 and a drive roller 36 are rotated through a drive motor 46 to remove the dust sticking to the surface of the filter 32. Then first the filter 32 in the part on which dust accumulates is sent into a dust removing case part 38. In this dust removing case part 38, a rotating oscillator 44 fixed to the shaft 42 is rotated, interlocked to the shaft 42, and the tip of the rotating oscillator 44 is jerked at the filter 32. Consequently, the sticking dust falls to be removed.