  We present results from the Suzaku observations of the dwarf nova SS Cyg in
quiescence and outburst in 2005 November. Owing to high sensitivity of the HXD
PIN detector and high spectral resolution of the XIS, we have determined
parameters of the plasma with unprecedented precision. The maximum temperature
of the plasma in quiescence 20.4 +4.0-2.6 (stat.) +/- 3.0 (sys.) keV is
significantly higher than that in outburst 6.0 +0.2-1.3 keV. The elemental
abundances are close to the solar ones for the medium-Z elements (Si, S, Ar)
whereas they decline both in lighter and heavier elements. Those of oxygen and
iron are 0.46 and 0.37 solar, respectively. That of carbon is exceptionally
high and 2 solar at least. The solid angle of the reflector subtending over the
optically thin thermal plasma is Omega/2\pi = 1.7+/-0.2 (stat.) +/-0.1 (sys.)
in quiescence. A 6.4 keV iron Ka line is resolved into a narrow and broad
components. These facts indicate that both the white dwarf and the accretion
disk contribute to the continuum reflection and the 6.4 keV iron Ka line. We
consider the standard optically thin boundary layer as the most plausible
picture for the plasma configuration in quiescence. The solid angle of the
reflector in outburst Omega/2\pi = 0.9 +0.5-0.4 and a broad 6.4 keV iron line
indicates that the reflection in outburst originates from the accretion disk
and an equatorial accretion belt. From the energy width of the 6.4 keV line, we
consider the optically thin thermal plasma in outburst as being distributed on
the accretion disk like solar coronae.
