The invention relates to an electrochromic device including a first non-tempered glass substrate (S1), the linear thermal expansion coefficient of which is between 35 and 60·10−7/° C., said substrate (S1) being coated with a stack including at least one transparent electrically conductive layer (2, 4), an electrochromic material layer (EC2), an ion-conductive electrolyte layer (EL), and a counter electrode (EC1).