  A new interpretation of cosmological redshifts is proposed to construct the
evolved-vacuum model of this phenomenon.The physical vacuum was considered to
be a real matter with time-dependent permittivity and permeability. Time
variation of these parameters 10^{-10} per year was shown on the base of
Maxwell's equations and Hubble's law to obey the exponential behavior causing
step-by-step decrease of light velocity with a rate of about 3m/s over 100
years. Cosmological aspects are discussed to explain some features of reality
of the Universe evolution.
