The acidic polymer hydrogel electrolyte was prepared from 1M H2SO4 aqueous solution, poly(vinyl alcohol) (PVA) and glutaraldehyde (GA). A new electric double layer capacitor (EDLC) with the polymer hydrogel electrolyte was assembled, and its electrochemical characteristics were investigated. As a result, the EDLC cell with the polymer hydrogel electrolyte exhibited almost the same discharge capacitance and high-rate dischargeability as that with a 1M H2SO4 aqueous solution as an electrolyte. It was also found that the self-discharge was remarkably suppressed by using the polymer hydrogel electrolyte. (c) 2005 Elsevier B.V. All rights reserved.