An irradiation device (1) and a method for the treatment of acne and acne scars, comprising at least one source of radiation (2), the source of radiation emitting at least one broadband spectrum in the wavelength range of 320-at least 540 nm and the radiation source (2) being pulse-operable and/or movable relatively to the area to be irradiated, the pulse energy being between 0.05-10 J/cm.sup.2 and the peak irradiation intensity being between 0.5 W/cm.sup.2 and 100 kW/cm.sup.2.