The present invention relates to an apparatus (20, 30) for curing radiation-curable coatings, which has at least one irradiation chamber (22, 32) provided with a plurality of UV radiation sources (18). It is provided according to the invention that a plurality of UV radiation sources (18) are arranged close to one another and interconnected to form one or more irradiation modules (10), the illuminance inside a irradiation module (10) and/or between at least two irradiation modules (10) being spatially variable.