  We propose a simple spectral model for the Seyfert 1 Galaxy MCG-6-30-15 that
can explain most of the 1 - 40 keV spectral variation by change of the partial
covering fraction, similar to the one proposed by Miller et al. (2008). Our
spectral model is composed of three continuum components; (1) a direct
power-law component, (2) a heavily absorbed power-law component by mildly
ionized intervening matter, and (3) a cold disk reflection component far from
the black hole with moderate solid-angle ({\Omega}/2{\pi} \approx 0.3)
accompanying a narrow fluorescent iron line. The first two components are
affected by the surrounding highly ionized thin absorber with N_H \approx
10^{23.4}cm-2 and log {\xi} \approx 3.4. The heavy absorber in the second
component is fragmented into many clouds, each of which is composed of radial
zones with different ionization states and column densities, the main body (N_H
\approx 10^24.2cm-2, log {\xi} \approx 1.6), the envelope (N_H \approx
10^22.1cm-2, log {\xi} \approx 1.9) and presumably a completely opaque core.
These parameters of the ionized absorbers, as well as the intrinsic spectral
shape of the X-ray source, are unchanged at all. The central X-ray source is
moderately extended, and its luminosity is not significantly variable. The
observed flux and spectral variations are mostly explained by variation of the
geometrical partial covering fraction of the central source from 0 (uncovered)
to \sim0.63 by the intervening ionized clouds in the line of sight. The ionized
iron K-edge of the heavily absorbed component explains most of the seemingly
broad line-like feature, a well-known spectral characteristic of MCG-6-30-15.
The direct component and the absorbed component anti-correlate, cancelling
their variations each other, so that the fractional spectral variation becomes
the minimum at the iron energy band; another observational characteristic of
MCG-6-30-15 is thus explained.
