PROBLEM TO BE SOLVED: To provide an air conditioner which uses a small amount of water more actively, reliably, easily, uniformly, and stably without leakage, cleans a cleaning target in a housing, keeps cleanliness, and easily maintains functions (for air cleaning, temperature rise, temperature decrease, ventilation, and heat exchange).SOLUTION: In the air conditioner, air outside a housing 5a flows through the housing 5a to clean an indoor fin heat exchanger 8 which is a cleaning target in the housing 5a. The air conditioner has a steam generator 21 which heats water to generate steam and a steam discharge body 20 which has a steam discharge port 20a opened with steam generated by the steam generator 21 directed toward the indoor fin heat exchanger 8 and discharging the steam generated by the steam generator 21, and mixes the steam with air for discharge to be applied to the indoor fin heat exchanger 8 at a temperature lower than 100°C.