Abstract: The present invention relates to a method and an apparatus for permanently or temporarily removing human hair, for miniaturizing the same or for changing the color thereof. This apparatus can also be used for coagulating blood vessels, veins or a selective injury of the derma collagen in order to regenerate the same. This apparatus uses one or more incandescent lamps (4) in which the radiation spectrum (34) can be modulated in order to heat slowly and efficiently the derma (17) and in order to heat locally the hair follicles (35). This apparatus also includes an optical system that converts the blue-green portion of the spectrum of the incandescent lamps (4) into a red region of the spectrum, that provides a highly efficient concentration of converted radiation from the incandescent filament (37) of the lamps (4) on the area of biological tissues to be treated, and that ensures a repeated recirculation towards the skin (17) of the radiation scattered by the same.