An interphase coating is formed by chemical vapor infiltration (CVI) on the fibers constituting a fiber preform, the interphase coating comprising at least an inner layer in contact with the fibers for embrittlement relief to the composite material, and an outer layer for bonding with the ceramic matrix. The fiber preform is then kept in its shape by the fibers provided with the interphase coating and is consolidated by being impregnated with a liquid composition containing a ceramic precursor, and by transforming the precursor into a ceramic matrix consolidation phase. The consolidated preform is then densified by an additional ceramic matrix phase. No support tooling is needed for forming the interphase coating by CVI or for densification after consolidation using the liquid technique.