To provide a composite material core more durable than ever, which decreases a manufacturing cost of the composite material core for use in an investment casting.

The composite material core (11) for the investment casting process comprises ceramic part (12) and high melting temperature metal part (13). The high melting temperature metal part is arranged so as to carry out multiple functions of high melting temperature metal elements. Particularly, the high melting temperature metal element fixed in a rear edge (17) of a ceramic element is extended beyond the front flat face of the ceramic element replacing the high melting temperature metal element which should have been otherwise needed to extend from the ceramic front end. Furthermore, the high melting temperature metal elements are extended beyond the space to be filled by wax forming body (14) in both front end and rear edge directions, in order to improve positioning and setting of the core in the wax formation process.