We prepare a vertically aligned multiwalled carbon nanotube (MWCNT) sheet by a transfer procedure from a silicon substrate, covered with catalyst grains as a CNT seedbed, to an aluminum sheet as a current collector for the application of the sheet to an electrode for an electric double-layer capacitor. It is noteworthy that the MWCNT sheet electrode provides a discharge capacity of 10-15 F g(-1) (of the aligned MWCNTs) even at an extremely high current density, 200 A g(-1), whereas no discharge capacitance is obtained at all with a typical high-performance activated carbon electrode at such a high current density. (c) 2007 The Electrochemical Society.