Body Plethysmography is a technique for studying the mechanics of external respiration: tracheobronchial resistance, extensibility of the lungs and chest, lung volumes, etc. The patient is placed in a special sealed cabin-a plethysmograph, in which he breathes through a tube communicating with the air outside the chamber. During the study, the breathing tube is closed with a flap for a short time and with the help of sensors, the pressure inside the cabin and the patient’s oral cavity (equivalent to intraalveolar pressure) is recorded. When the flap is opened, the volume velocity of inhalation and exhalation is determined. Body Plethysmography is used to examine patients with bronchial asthma, emphysema of the lungs, obstructive bronchitis. The cost of the service is affected by the complexity of the protocol.