  An observation of the West lobe of radio galaxy Fornax A (NGC 1316) with
Suzaku is reported. Since Feigelson et al. (1995) and Kaneda et al. (1995)
discovered the cosmic microwave background boosted inverse-Comptonized (IC)
X-rays from the radio lobe, the magnetic field and electron energy density in
the lobes have been estimated under the assumption that a single component of
the relativistic electrons generates both the IC X-rays and the synchrotron
radio emission. However, electrons generating the observed IC X-rays in the 1
-- 10 keV band do not possess sufficient energy to radiate the observed
synchrotron radio emission under the estimated magnetic field of a few micro-G.
On the basis of observations made with Suzaku, we show in the present paper
that a 0.7 -- 20 keV spectrum is well described by a single power-law model
with an energy index of 0.68 and a flux density of 0.12+/-0.01 micro-Jy at 1
keV from the West lobe. The derived multiwavelength spectrum strongly suggests
that a single electron energy distribution over a Lorentz factor gamma = 300 -
90000 is responsible for generating both the X-ray and radio emissions. The
derived physical quantities are not only consistent with those reported for the
West lobe, but are also in very good agreement with those reported for the East
lobe.
