an imager configured to capture an image of a suction portion of a drain pump or a discharge pipe of the drain pump in a casing of an air treatment device;

a processor configured to estimate contamination information on the suction portion of the drain pump or the discharge pipe of the drain pump based on an estimation model created by machine learning using, as input data, image data captured by the imager and operation data of the air treatment device and/or environment data related to an environment in which the air treatment device is provided; and

a notifier configured to output the contamination information as a notification to a service provider, wherein the notification enables the suction portion of the drain pump or the discharge pipe of the drain pump in the casing to be cleaned based on the outputted contamination information.