The microstructure of the porous Cr-Al metal-oxide cermet was studied by means of XRD, SEM, EDX as well as IR and Raman spectroscopy. This cermet was synthesized by mechanical alloying of Cr-Al powders in an AGO-2 planetary ball mill followed by hydrothermal treatment in a special stainless steel die and calcination in air. As a result, a highly porous monolith comprised of metal-like particles randomly distributed in the oxide matrix (Cr2O3 and Al2O3) was formed. Two types of the composite cores were found in cermets. The first one consisted of chromium phase containing nanoparticles sized from 50 to 140 nm and Al-enriched phase at the interfaces. The second one consisted of new chromium oxide phases with hexagonal Cr2N-like and fcc CrN-like structures probably with Cr2O and CrO stoichiometry. These new phases were stabilized within aggregates of the nanocomposite particles containing inclusions of alumina. The relations between different preparation stages and the cermet microstructure are discussed.