An air conditioning apparatus includes: a casing that includes an inlet port that takes in air and an outlet port to which a blow-out duct is connected, the casing forming an airflow path extending from the inlet port to the outlet port; a fan unit that is disposed in the casing and sends air from the inlet port to the outlet port in the airflow path; a ventilation member that is disposed in the airflow path and allows air to pass therethrough; a differential pressure gauge that measures a differential pressure between points in front of and behind the ventilation member; and a controller that adjusts a rotational speed of the fan unit based on a measured value of the differential pressure gauge.