PURPOSE: To obtain a small electric automobile causing no contamination where charging time is shortened by inverting DC output from an electrical double layer capacitor into VVVF AC power for driving a motor.

CONSTITUTION: 10 pts.wt. of active carbon powder (specific surface area 2000m2/g, grain size 2μm) and 2 pts.wt. of acetylene black are dispersed into a mixed liquid of water and methanol. 2 pts.wt. of carboxymethylcellulose is dissolved into the water. Both aqueous liquids are then mixed and stirred to produce an active carbon slurry which is then subjected to roughening and applied onto the opposite sides of an aluminum foil 10. The aluminum foil 10 is then dried to produce foil electrodes 13, 14 composed of active carbon electrodes 11, 12 which are then wound together with a separator 15 and encapsulated in an aluminum case 16 together with an electrolyte and lead wires 17, 18 are further provided to constitute an electrical double layer capacitor 1. The electrolyte is prepared by dissolving tetraethylammonium tetrafluoroborate into propylenecarbonate liquid. Output from the capacitor 1 is employed as power supply.