A process for the preparation of an ultra-refractory composite ceramic material comprising: (i) preparing at least one preform comprising carbon fibers; (ii) infiltrating said at least one preform with a ceramic suspension comprising: (a) a mixture of ceramic phases comprising: 70-95 vol.% of an ultra-refractory ceramic component selected from among ZrB 2, HfB 2, TaB 2, ZrC, HfC, TaC and mixtures thereof; 3-10 vol.%, preferably 3-8 vol.%, of a sintering aid selected from among ZrSi 2, Si 3 N 4 and mixtures thereof, preferably Si 3 N 4; and 2-20 vol.%, preferably 2-10 vol.%, more preferably 2-5 vol.% of a Si compound selected from among SiC, at least one organic precursor of SiC and mixtures thereof, preferably SiC; and (b) a dispersing medium selected from among water, at least one organic solvent and mixtures thereof, preferably water, thereby obtaining a composite material; (iii) drying the composite material under vacuum at a pressure comprised between 1 × 10 5 and 1 × 10 -1 Pa; and (iv) consolidating the dried composite material at a temperature comprised in the range of 1700°-2000°C, wherein the carbon fibers are present in the ultra-refractory composite ceramic material in an amount comprised in the range of 30-70 vol. %. (i) preparing at least one preform comprising carbon fibers; (ii) infiltrating said at least one preform with a ceramic suspension comprising: (a) a mixture of ceramic phases comprising: 70-95 vol.% of an ultra-refractory ceramic component selected from among ZrB 2, HfB 2, TaB 2, ZrC, HfC, TaC and mixtures thereof; 3-10 vol.%, preferably 3-8 vol.%, of a sintering aid selected from among ZrSi 2, Si 3 N 4 and mixtures thereof, preferably Si 3 N 4; and 2-20 vol.%, preferably 2-10 vol.%, more preferably 2-5 vol.% of a Si compound selected from among SiC, at least one organic precursor of SiC and mixtures thereof, preferably SiC; and (b) a dispersing medium selected from among water, at least one organic solvent and mixtures thereof, preferably water, thereby obtaining a composite material; (a) a mixture of ceramic phases comprising: 70-95 vol.% of an ultra-refractory ceramic component selected from among ZrB 2, HfB 2, TaB 2, ZrC, HfC, TaC and mixtures thereof; 3-10 vol.%, preferably 3-8 vol.%, of a sintering aid selected from among ZrSi 2, Si 3 N 4 and mixtures thereof, preferably Si 3 N 4; and 2-20 vol.%, preferably 2-10 vol.%, more preferably 2-5 vol.% of a Si compound selected from among SiC, at least one organic precursor of SiC and mixtures thereof, preferably SiC; and 70-95 vol.% of an ultra-refractory ceramic component selected from among ZrB 2, HfB 2, TaB 2, ZrC, HfC, TaC and mixtures thereof; 3-10 vol.%, preferably 3-8 vol.%, of a sintering aid selected from among ZrSi 2, Si 3 N 4 and mixtures thereof, preferably Si 3 N 4; and 2-20 vol.%, preferably 2-10 vol.%, more preferably 2-5 vol.% of a Si compound selected from among SiC, at least one organic precursor of SiC and mixtures thereof, preferably SiC; and (b) a dispersing medium selected from among water, at least one organic solvent and mixtures thereof, preferably water, thereby obtaining a composite material; (iii) drying the composite material under vacuum at a pressure comprised between 1 × 10 5 and 1 × 10 -1 Pa; and (iv) consolidating the dried composite material at a temperature comprised in the range of 1700°-2000°C,