Abstract: Scattering-type long wave pass filters for the infrared region of the spectrum offer high levels of suppression of the unwanted short-wave radiation, good levels of transmission of the desired long wave radiation combined with good control of the rejection edge position and shape and good mechanical stability of the filter layer. Such filters are well suited for the wide range of applications and can be used in various environments including cryogenic temperatures. Several methods of fabrication of such filters based on electrochemical etching of semiconductor materials in order to form porous layer are provided.