  We present the Suzaku results of eta Carinae in the 5--50 keV range conducted
twice around the apastron in 2005 August for 50 ks and in 2006 February for 20
ks. The X-ray Imaging Spectrometer (XIS) produced hard (5--12 keV) band
spectra, resolving K shell lines from highly ionized Fe and Ni. The Hard X-ray
Detector yielded a significant detection in the super-hard (15--50 keV) band,
which is uncontaminated by near-by sources. We constrained the temperature of
the optically-thin thermal plasma emission dominant in the hard band as 3--4
keV using the K-shell line features with the XIS. We found significant excess
emission above the thermal emission in the super-hard band with the PIN,
confirming the previous INTEGRAL ISGRI report. The entire 5--50 keV spectra
were fitted by a combination of a thermal plasma model plus a flat power-law or
a very hot thermal bremsstrahlung model for the excess emission. No significant
change of the excess emission was found at different epochs within the
systematic and statistical uncertainties and no flare-like flux amplification
was seen in the hard band, indicating that the excess emission is a steady
phenomenon. We argue that the super-hard emission is attributable to the
inverse Compton of stellar UV photons by non-thermal electrons or to the
thermal bremsstrahlung of very hot plasma, and not to the bremsstrahlung by
non-thermal electrons colliding with cold ambient matter.
