To prevent clogging of drain piping by controlling a drain pump in a case when a drainage water discharge method is applied for force feeding the drainage water by the drain pump.

This air conditioner comprises a drain pan for collecting the drainage water dropping from a heat exchanger, and the drain pump for discharging the drainage water in the drain pan. To prevent the clogging of drain piping, a rotational frequency of the drain pump is increased when rotating torque of a DC motor for driving the drain pump is increased, to increase a discharge rate of the drain pump. Further in this conditioner, the drain pump may be operated with delay of a prescribed time from the start of the operation of the air conditioner, or may be operated at prescribed intervals during the operation of the air conditioner.

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