  We describe a THz spectrometer operating between 1.2 and 10.5 THz, consisting
of band pass filters made with metasurfaces. The source is made of 10 W small
black body. The detector is a high sensitivity room temperature pyroelectric
sensor. Various techniques used to prepare samples are described. The spectra
obtained are compared with those measured with a Fourier Transformer Infrared
Spectrometer on the same samples. The instrument, using commercial technologies
available at the present time, can constitute an economical alternative to very
expensive spectrometers. It has already been successfully used, getting precise
spectroscopic measures of many inorganic powders.
