One of the recent achievements at the Laboratory of Astronomy and Applied Optics of the University of Athens is the construction of a medium-resolution stellar spectrograph. The instrument was initially built for laboratory applications and later was modified for astronomical use. The installation of the stellar spectrograph on the telescope of the University of Athens Observatory was successful, despite the heavy light pollution, and is characterized as the beginning of spectroscopic observations from an observatory in Athens. The stellar spectrograph has a resolution of 48000 with a limiting resolution of 0.1Å. It can be used for spectral classification for stars brighter than 9mag, for studies of fast rotating stars and the detection (possibly discovery) of binary stars among single ones.