  The Crab Nebula has been observed by the HEGRA stereoscopic system of 4
imaging air Cherenkov telescopes (IACTs) for about 100 hours from 1997
September to 1998 March. The recent detailed studies on the system performance
give an energy threshold and an energy resolution for gamma-rays of 500 GeV and
\~20 %, respectively. The Crab spectrum was measured with the IACTs system in a
very broad energy range from 500 GeV to 25 TeV, using the observations at
zenith angles up to 50 degree. The pure power-law spectrum in TeV gamma-rays
constrains the physics parameters of the nebula environment as well as the
models of photon emission.
