Abstract: Device for automatically controlling the lighting level of premises (A) having available one or more openings (B) to the outside. This device acts on means (V, S, E) of masking the openings and on means of artificial lighting with dimmer (L) as a function of a set point value corresponding to a lighting level established by the user and recorded instantaneously. The masking and lighting means are furthermore controlled in a specified order so as to limit the consumption of energy. In certain implementations, this order is determined as a function of the deviation between a measured temperature and a threshold temperature.