Abstract: A foundry shell core includes an outer shell made of a polymerised sand and resin mixture suitable for withstanding the heat and metallostatic pressure produced by molten metal during casting, and of an inner core body made of a material suitable for being thermally dissolved before using the shell core forming an inner cavity inside the core itself that facilitates the intake of smoke and gases produced during the casting. Alternatively, the inner core body is dissolved after the solidification of the casting. The shell cores are obtained by injection with the use of a conventional core box into which the core bodies, previously obtained by a die, have been inserted.