Abstract: A system for ultraviolet irradiation of objects and a method of using this system is disclosed. The system includes: an illuminating device positioned in a center section of an octagon shaped a base area and including one or more elongated light sources, each emitting ultraviolet light given by shortwave ultraviolet light (UV-C light) and extending in parallel to a normal on the base area; a set of rotatable mesh grids arranged around the base area such that the mesh grids surround the illuminating device and configured to be equipped with the objects; and a set of reflectors including a set of movable side reflectors, wherein the reflectors are configured to be arranged such, that they form a resonator surrounding the mesh grids surrounding the illuminating device.