We present an XMM-Newton observation of the radio-quiet quasar Q0056-363 ( z=0.162 ) .
This is the first time that this quasar is observed in the hard X-ray range ( above 2 keV ) .
We find that Q0056-363 is a powerful X-ray quasar , with a 0.3–12 keV unabsorbed luminosity of about 1.2 \times 10 ^ { 45 } erg s ^ { -1 } 
with the largest part ( \sim 67 \% ) emitted below 2 keV .
The spectrum reveals a large featureless soft X-ray excess below 2 keV and a strong broad Fe K _ { \alpha } line at 6.4 keV ( in the quasar frame ) .
The Fe K _ { \alpha } line is due to low to moderate ionization states of iron ( i.e. , < Fe xvii ) , with an equivalent width of about 250 eV and a velocity width of about 25,000 km s ^ { -1 } .
Q0056-363 is presently the most luminous AGN known to exhibit such a broad and intense Fe K _ { \alpha } line profile from near neutral iron .
The line can be fitted with a relativistic profile from an accretion disc around either a Schwarzschild ( non-rotating ) or a Kerr ( rotating ) black hole .
A combination of two thermal Comptonization components and a disc reflection model is favored to explain both the continuum over the energy range 0.3–12 keV and the Fe K _ { \alpha } line .
A patchy corona covering a large part of the inner disc surface is needed in order to be compatible with the accretion rate inferred from the spectral energy distribution of Q0056-363 , unless the mass of the black hole is much higher than about 5 \times 10 ^ { 8 } M _ { \odot } .