There is disclosed a method of mixing/dispersing solid phases of a carbon powder 4 and silicon powder 5, impregnating a woven fiber 2 with the powders, and subsequently exposing the woven fiber to a high temperature sufficient for reaction calcining to react/calcine the woven fiber, so that only small amounts of C and Si particles remain, a matrix forming speed is high, and CMC having high airtightness can be manufactured in a short time.