Abstract: A maintenance and management system for tracheal tube in tracheal intubation makes it easier or steadier to identify endotracheal tube placement in the airway, check a tracheal stenosis due to sputum clogging, confirm a breakaway of the tube out of the airway, store and monitor measured data, diagnose automatically the complications, and obtain data for reproducing function of sound in a breath circuit. A ventilator tube is connected to the endotracheal tube and provided therein with a microphone to sense a breath sound transmitted via the endotracheal tube and a pressure sensing element to measure a circuit pressure in the ventilator circuit for the endotracheal tube. The data derived from the sensing elements is processed in a personal computer to be used to measure whether the breath sound and the circuit pressure are within a range of a prescribed value.