The invention relates to a method for producing a ceramic core (4, 4)and to a core produced by this methodfor preparing the production of a casting having hollow structures which the ceramic core is configured to form, making use of a 3D model of digital geometric co-ordinates of the casting, wherein the method comprises the following steps: a) Producing by means of casting technology at least one first portion (4) of the ceramic core including at least one first joining structure (24) in a surface of the portion; b) Producing by means of casting technology or 3D printing technology at least one second portion (4) of the ceramic core including at least one second joining structure (26) matching the first joining structure, in a surface of the portion, wherein the production by means of casting technology comprises the following steps: i. Unpressurized or low-pressure casting of a ceramic core blank, and specifically with an oversize relative to the core (4, 4) according to the geometric co-ordinates; ii. CNC processing of the core (4, 4), according to the 3D model, in a first CNC processing method; c) joining the at least one first and at least one second portion of the core at the matching joining structures to form the core according to geometric co-ordinates of the casting.