Abstract: The invention relates to cleaning method and cleaning apparatus of air-conditioner used in the operation for cleaning and removing the contamination of the heat exchanger (condenser, evaporator) for composing an air-conditioner, for example, one-package type air-conditioner and separate type air-conditioner, and more particularly to an air-conditioner cleaning method and its cleaning apparatus capable of securely cleaning and removing the dirt sticking to the heat exchanger to the deepest parts, by keeping the open side of the spraying guide body in contact with the cleaning parts of the heat exchanger for composing an air-conditioner, connecting detergent feed means to the closed side of the spraying guide body through an injection pipe, spraying the detergent supplied from the detergent feed means to the area enclosed by the spraying guide body, and cleaning and removing the dirt sticking to the heat exchanger by the foamy detergent, while preventing splash-back of the detergent.