Abstract: The device is to be mounted on any individual chandelier or any form of lamp: normal bulb (10), fluorescent, neon, sodium mercury vapor etc. When the space is not illuminated very much, the lamp (10) in consequence of the electronic circuit contained in the device according to the invention (1) lights up with an intensity so as to compensate for the reduction of the illumination of the surroundings.The device therefore controls every individual lamp economizing energy because unlike the known devices controlling groups of lamps it acts so as to subdue the light emitted by the lamp or bulb gradually the more the space surrounding it is illuminated. The luminous energy emitted is inversely proportional to the luminous intensity of the surrounding space. The luminous energy of the space is preferably communicated to the device (1) by means of a bundle of optical fibres (2) avoiding the light reflected by the shield (14) of the lamp.