Context :

Aims : We analysed the Suzaku XIS1 data of the A 3112 cluster of galaxies in order to examine the X-ray excess emission in this cluster reported earlier with the XMM-Newton and Chandra satellites .

Methods : We performed X-ray spectroscopy on the data of a single large region .
We carried out simulations to estimate the systematic uncertainties affecting the X-ray excess signal .

Results : The best-fit temperature of the intracluster gas depends strongly on the choice of the energy band used for the spectral analysis .
This proves the existence of excess emission component in addition to the single-temperature MEKAL in A 3112 .
We showed that this effect is not an artifact due to uncertainties of the background modeling , instrument calibration or the amount of Galactic absorption .
Neither does the PSF scatter of the emission from the cool core nor the projection of the cool gas in the cluster outskirts produce the effect .
Finally we modeled the excess emission either by using an additional MEKAL or powerlaw component .
Due to the small differencies between thermal and non-thermal model we can not rule out the non-thermal origin of the excess emission based on the goodness of the fit .
Assuming that it has a thermal origin , we further examined the Differential Emission Measure ( DEM ) models .
We utilised two different DEM models , a Gaussian differential emission measure distribution ( GDEM ) and WDEM model , where the emission measure of a number of thermal components is distributed as a truncated power law .
The best-fit XIS1 MEKAL temperature for the 0.4–7.0 keV band is 4.7 \pm 0.1 keV , consistent with that obtained using GDEM and WDEM models .

Conclusions :