Context :

Aims : X-ray observations of gravitationally lensed quasars may allow us to probe the inner structure of the central engine of a quasar .
Observations of Q2237+0305 ( Einstein Cross ) in X-rays may be used to constrain the inner structure of the X-ray emitting source .

Methods : Here we analyze the XMM- \it { Newton } observation of the quasar in the gravitational lens system Q2237+0305 taken during 2002 .
Combined spectra of the four images of the quasar in this system were extracted and modelled with a power-law model .
Statistical analysis was used to test the variability of the total flux .

Results : The total X-ray flux from all the images of this quadruple gravitational lens system is 6 \cdot 10 ^ { -13 } erg/ ( cm ^ { 2 } \cdot sec ) in the range 0.2–10 keV , showing no significant X-ray spectral variability during almost 42 ks of the observation time .
Fitting of the cleaned source spectrum yields a photon power-law index of \Gamma = 1.82 _ { -0.08 } ^ { +0.07 } .
The X-ray lightcurves obtained after background subtraction are compatible with the hypothesis of a stationary flux from the source .

Conclusions :