An electrochromic display device which comprises a display electrode comprising a transparent substrate, a transparent electrode formed on an inner surface of the transparent substrate and an electrochromic material layer for display made of tungstgen oxide and formed on the transparent electrode; a counter electrode comprising a substrate, a conductive layer formed on an inner surface of the substrate and an activated carbon fiber cloth bonded to the conductive layer with a conductive adhesive; and a spacer provided beween the display electrode and the counter electrode with their inner surfaces facing to each other to define, between them, an electrolyte chamber, which is filled with an electrolyte comprising LiClO.sub.4 dissolved in propylene carbonate containing water and an acid, which device has an increased original injected charge and good maintenance of the injected charge after prolonged storage.