Abstract: The invention relates to an optically structured filter with predominantly smooth or planar surfaces. Such filters are used as primary masks for the photolithographically manufacturing microelectronic elements, having with at least one pattern with a different transmission in relation to an electromagnetic radiation to be filtered. A filter layer consists of a material of locally homogeneous transmission into which ions, preferably metal ions with an energy of more than 1 keV, are implanted for producing the pattern(s) with the different transmission. This makes it possible to produce filters having patterns with regions of different transmissions for various wave lengths. Suitable materials to be used for the filter layer are materials such as inorganic and organic polymers and glasses as well as mono- and polycrystalline oxides or nitrides. The ion implantation itself is carried out by means of process steps known per se.