  We report the discovery of an X-ray counterpart of the unidentified very high
energy gamma-ray source HESS J1427-608. In the sky field coincident with HESS
J1427-608, an extended source was found in the 2-8 keV band, and was designated
as Suzaku J1427-6051. Its X-ray radial profile has an extension of sigma=0.9'
+/- 0.1' if approximated by a Gaussian. The spectrum was well fitted by an
absorbed power-law with N_H=(1.1 +/- 0.3) times 10^23 cm^-2, Gamma=3.1
+0.6/-0.5, and the unabsorbed flux F_X=(9 +4/-2) times 10^-13 erg s^-1 cm^-2 in
the 2-10 keV band. Using XMM-Newton archive data, we found seven point sources
in the Suzaku source region. However, because their total flux and absorbing
column densities are more than an order of magnitude lower than those of Suzaku
J1427-6051, we consider that they are unrelated to the Suzaku source. Thus,
Suzaku J1427-6051 is considered to be a truly diffuse source and an X-ray
counterpart of HESS J1427-608. The possible nature of HESS J1427-608 is
discussed based on the observational properties.
