The invention concerns an electrochromic device comprising a single supporting substrate (1) on which are disposed a working electrode (6) which is electrochromic per se and/or bears an electrochromic material on at least a portion thereof; a counter electrode (3); and a layer of an electrically insulating material (4) separating the electrodes; wherein said electrochromic material has a major surface at least a portion of which forms at least a portion of an external surface of the device. The new device allows deposition of electrochromic coatings on a variety of substrates which need not be transparent.