Various approaches such as ventilator management involving lung-protective ventilation, corticosteroids, prone positioning, and nitric oxide have failed to maintain sufficient lung oxygenation or appropriate ventilation competence in very severe acute respiratory distress syndrome (ARDS). Extracorporeal membrane oxygenation (ECMO) has been aggressively introduced for such patients, although in only a few institutions. The clinical usefulness of ECMO in a large-scale multicenter study (CESAR trial, 2009) and continued development/improvement of ECMO devices have facilitated performance of ECMO, with further increase in the number of institutions adopting ECMO therapy. Clinical usefulness of ECMO was documented in many cases of severe ARDS secondary to influenza A (H1N1) 2009 infection. ECMO requires establishment of an appropriate management system to minimize fatal complications (e.g., hemorrhage), which requires a multidisciplinary team. This, in combination with a new technique, interventional lung assist, will further extend the indications for ECMO. ECMO can be expected to gain importance as a respiratory support technique.