A process for the manufacture of a thin ceramic core involves casting a band of uniform thickness on a support from a solution of a ceramic material based on silica and zircon in a binder, drying the band, shaping the band in a mold and carrying out preheating and pressing of the band in the mold, baking the component thus obtained in a ceramic preform, and then carrying out an impregnation. The thin core obtained can be assembled together with another thin core and/or on a conventional thick central core, and can be used in precision casting such as in the production of turbine blades.