A catalyst regenerator according to an embodiment of the present invention, as a catalyst regenerator that regenerates a coked catalyst separated from a product produced in an endothermic catalytic reaction of a fluidized bed reactor, includes: a reaction chamber that includes a regeneration space, receives the coked catalyst from a standpipe connected to the regeneration space, and discharges a regenerated catalyst to an outlet; a fuel supplier that is connected to the reaction chamber to inject a fuel for combustion into the regeneration space; and a fuel supplier that is connected to the reaction chamber to inject an air for combustion into the regeneration space, wherein the fuel injected from the fuel supplier is a reformed fuel containing hydrogen and carbon monoxide.