A 6-year-old boy had cold-like symptoms and was diagnosed with influenza A at a clinic. Administration of oseltamivir and azithromycin did not improve the symptoms. He was referred to our hospital and was diagnosed with H1N1 pneumonia. The patient required ventilator support. However, hypoxia and hypercapnia were uncontrollable. To oxygenate and reduce the carbon dioxide concentration, veno-venous extracorporeal membrane oxygenation (ECMO) was applied 24 h after admission. We established outflow via the right internal jugular vein and inflow via the right femoral vein. Six hours later, an electrical storm of ventricular fibrillation occurred, probably due to influenza myocarditis. Chest compression was started immediately. Both cardioversion and medication were ineffective in treating the electrical storm. Therefore, we decided to switch the veno-venous ECMO to veno-arterial ECMO to maintain systemic flow. During chest compression, a 6-mm graft was anastomosed to the left common femoral artery, and an outflow tube was connected to the graft. Consequently, veno-arterial ECMO was established via outflow through the left common femoral artery and inflow through both the right jugular vein and right femoral vein. Veno-arterial ECMO terminated the electrical storm, and cardiac output improved. Veno-arterial ECMO was provided for 107 h, and was then replaced by veno-venous ECMO. Forty-three hours later, veno-venous ECMO was discontinued. The patient was successfully weaned from the mechanical ventilator on the 9th day after admission. Unfortunately, spinal infarction appeared as a complication. The patient was discharged from the hospital on the 86th day, and has now returned to primary school.