The electrical activity of the diaphragm (EAdi) shows global diaphragmatic activation and power output from the central nervous system. We measured the EAdi as an indicator of breathing workload in a 40-year-old man suffering from severe acute respiratory distress syndrome (ARDS) secondary to influenza pneumonia in the process of weaning from extracorporeal membrane oxygenation (ECMO). Turning off the sweep gas flow immediately led to EAdi elevation, followed by hypoxia. The patient was successfully weaned from ECMO by reference to EAdi. This is the first case report to suggest that EAdi monitoring might be useful for ARDS patients during ECMO weaning.