  We present the results of a broadband (0.5-78 keV) X-ray spectral study of
the persistent Galactic black hole X-ray binary GRS 1758-258 observed
simultaneously by Swift and NuSTAR. Fitting with an absorbed power-law model
revealed a broad Fe line and reflection hump in the spectrum. We used different
flavours of the relativistic reflection model for the spectral analysis. All
models indicate the spin of the black hole in GRS 1758-258 is >0.92. The source
was in the low hard state during the observation, with the hot electron
temperature of the corona estimated to be kT$_e$ ~ 140 keV. The black hole is
found to be accreting at ~1.5 % of the Eddington limit during the observation,
assuming the black hole mass of 10 $M_{\odot}$ and distance of 8 kpc.
