CARBON FIBER COMPOSITE, PROCESS FOR PRODUCING SAME, CATALYST-CARRYING BODY AND POLYMER ELECTROLYTE FUEL CELL

A conventional catalyst support obtained by making platinum fine particles supported on carbon particles has a problem that the platinum fine particles have undergone agglomeration, insufficient dispersion or the like and therefore are not in such a state that the fine particles of the original sizes are uniformly dispersed on the carbon particles, thus deteriorating the catalytic properties . The problem can be solved by a process for producing a carbon fiber composite which comprises: a step of subjecting metal fine particles of either at least one metal or a compound containing the metal to reductive deposition on fine cellulose having carboxyl groups on the crystal surface to make a composite composed of both the fine cellulose and the metal fine particles; and a step of carbonizing the fine cellulose of the composite to prepare a carbon fiber composite.