  We present the main results of a deep timing analysis (in the 0.2-10 keV
energy band) of the bright Seyfert-1 galaxy MCG-6-30-15 performed on XMM-Newton
data. The light-curves and hardness ratios show that the source has large flux
and spectral variations on time-scales of a few kiloseconds at most. From the
analysis of both the power spectra and the structure function of the light
curves we detected a relevant source variability between time-scales of ~0.3
and ~10 ks. Based on this result, we extracted a characteristic size of the
X-ray emitting region of the order of 10^13 cm.
