Provided is a fuel cell catalyst composition comprising a C12A7:X− inorganic material having a structure in which oxygen anions of C12A7 are replaced by halogen (X) anions, or comprising a C12A7:X−-based inorganic material which is a C12A7:X− partially converted to electride. A fuel cell comprising the fuel cell catalyst composition in a catalyst layer is also provided. Also provided is a method of producing a fuel cell catalyst composition, comprising a step of heat-treating C12A7:X− at temperature of 1000-1300° C. for at least 20 hours under a nitrogen atmosphere.