The present invention relates to a catalyst carrier characterized by the fact that it comprises a substance which promotes a transition of an alumina that can be converted to .alpha.-alumina, which substance is located near the surface of a carrier composed mainly of alumina and which carrier is subjected to a heat treatment under appropriate conditions, thereby causing the transition of said alumina to .alpha.-alumina, with those pores near the surface made larger in diameter than those pores located more deeply within the carrier. The invention also includes a method of manufacturing said catalyst carrier.