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Matter flows in the central regions of quasars during their active phases areprobably responsible for the properties of the super-massive black holes andthat of the bulges of host galaxies. To understand how this mechanism works, weneed to characterize the geometry and the physical state of the accretingmatter at cosmological redshifts. The few high quality X-ray spectra of distantQSO have been collected by adding sparse pointings of single objects obtainedduring X-ray monitoring campaigns. This could have introduced spurious spectralfeatures due to source variability. Here we present a single epoch,high-quality X-ray spectrum of the z=3.62 quasar B1422+231 whose flux isenhanced by gravitationally lensing (F$_{2-10 keV}\sim$10$^{-12}$erg s$^{-1}$cm$^{-2}$). The X-ray spectrum of B1422+231 is found to be very similar to theone of a typical nearby Seyfert galaxy. Neutral absorption is detected(N$_{H}\sim$5$\times$10$^{21}$ cm$^{-2}$ at the redshift of the source) while astrong absorption edge is measured at E$\sim$7.5 keV with an optical depth of$\tau\sim$0.14. We also find hints of the FeK$\alpha$ line in emission atE$\sim$6.4 keV line (EW$\lesssim$70 eV) and a hump is detected in theE$\sim$15-20 keV energy band (rest-frame) suggesting the presence of areflection component. In this scenario, the primary emission of B1422+231 ismost probably dominated by the thermal Comptonization of UV seed photons in acorona with kT$\sim$40 keV and the reflection component has a relativedirect-to-reflect normalization r$\sim$1. These findings confirm thatgravitational lensing is effective to obtain good quality X-ray spectralinformation of quasar at high-z, moreover they support the idea that the samegeneral picture characterizing active galactic nuclei in the nearby Universe isvalid also at high redshift.

XMM-Newton reveals a Seyfert-like X-ray spectrum in the z=3.6 QSO B1422+231