An attempt was made to recover the strength of a PIP-processed SiC/SiC composite exposed in air at high temperatures by means of the deoxidization treatment with CO gas. By deoxidation treatment at 1723 and 1823 K for the composite specimen oxidized at 1573 K, the strength of deoxidized specimens became higher by around 4 and 1.5 times than that of oxidized one, respectively.