Abstract: A method and an apparatus for phototherapy or tanning of the human body utilizes energy most efficiently by generating incoherent excimer radiation in the wavelength bands of between 300 and 310 nm, preferably about 308 nm, and from 315 to 350 nm. A discharge space (4) is defined by a discharge vessel (3) of radiation transmissive dielectric material. A first electrode (5), preferably a mesh or a net jacket, surrounds the wall of the discharge vessel; a second electrode (7) covered by a second dielectric (8) is coaxially located within the discharge vessel. A fill of xenon halide, preferably xenon chloride with a cold-fill pressure of about 500 to 1,500 mbar is located within a discharge space (4). A voltage source (15) is connected to said first and second electrodes.