To provide a method for producing a ceramic fiber-based composite material by which the reaction of a melted silicon penetrating a crack part with a boron nitride layer is effectively suppressed, even if the crack part exists in a silicon carbide layer formed on the boron nitride layer on a surface of a fiber, and an interface layer is laid between the obtained matrix and the fiber.

This ceramic fiber-based composite material is constituted of a matrix 1 of ceramics consisting essentially of a main phase of SiC formed by performing reaction sintering and ceramic fibers 2 of the SiC formed into the composite with the matrix 1. An interface layer previously coated on the fiber 2 is arranged between the fiber 2 and the matrix 1. The interface layer has a BN layer 3 covering the surface of the fiber 2 and having 0.4μm thickness, a C layer 5 covering the BN layer 3 and having 0.2μm thickness and a SiC layer 4 covering the C layer and having 0.4μm thickness.