  The Tunka Advanced Instrument for Gamma- and cosmic-ray Astronomy (TAIGA) is
a multicomponent experiment for the measurement of TeV to PeV gamma- and cosmic
rays. Our goal is to establish a novel hybrid direct air shower technique,
sufficient to access the energy domain of the long-sought Pevatrons. The hybrid
air Cherenkov light detection technique combines the strengths of the HiSCORE
shower front sampling array, and two $\thicksim$4 m class, $\sim$9.6 deg field
of view Imaging Air Cherenkov Telescopes (IACTs). The HiSCORE array provides
good angular and shower core position resolution, while the IACTs provide the
image shape and orientation for gamma-hadron separation. In future, an
additional muon detector will be used for hadron tagging at $\ge$ 100 TeV
energies. Here, only data from the first IACT of the TAIGA experiment are used.
A random forest algorithm was trained using Monte Carlo (MC) simulations and
real data, and applied to 85 h of selected observational data tracking the Crab
Nebula at a mean zenith angle of 33.5 deg, resulting in a threshold energy of 6
TeV for this dataset. The analysis was performed using the gammapy package. A
total of 163.5 excess events were detected, with a statistical significance of
8.5 sigma. The observed spectrum of the Crab Nebula is best fit with a power
law above 6 TeV with a flux normalisation of $(3.20\pm0.42)\cdot10^{-10}
TeV^{-1} cm^{-2} s^{-1})$ at a reference energy of 13 TeV and a spectral index
of $-2.74\pm0.16$.
