PURPOSE: To obtain a ceramic fiber system for reinforcing a metal matrix composite material, hardly being damaged and capable of keeping the strength, even by the thermal shock caused by deposition of molten metal matrix on the coated fiber system when producing the metal matrix composite material.

CONSTITUTION: This ceramic fiber system is constituted of a ceramic core fiber having a side surface, the first coating layer connected to the side surface of the sore wire, and the second coating layer arranged around the core fiber, having a structure different from the first coating layer, and forming a peelable interface between the layer and the first layer. When stress by the thermal shock is added to the composite material at the time of the production of the composite material, the second layer is properly peeled from the first coating layer at the peelable interface to buffer the thermal shock. As a result, the strength of the ceramic core fiber is maintained. The coated ceramic fiber system is usable for a gas turbine engine or the like to be exposed to high temperature.