To provide a drain pump operation control device capable of controlling the operation and shutdown of a drain pump by detecting the water level of drain water without causing an increase in the cost and contriving a longer service life of the drain pump.

This drain pump operation control device is designed to operate intermittently a drain pump 1 with a microcomputer 16 and detects the rotary speed when the drain pump 1 operates intermittently with a magnet 5 fixed with a rotary shaft 3 and a hole sensor 7 and computes a drain water level from an elapsed time L3 that this rotary speed rises to a rise threshold value n0 and drops to a drop threshold value t3. When this drain water level exceeds a prescribed value L1, the drain pump is arranged to operate in continuous mode only for a continuous operation time for a predetermined few minutes. When the drain water level has failed to reach the prescribed value L1, the operation of the drain pump 1 comes to a halt, thereby contriving to extend the longer service life of the drain pump 1.