It is an object of the present invention to provide a ferrite particle having a low apparent density, and being capable of maintaining various properties thereof in controllable states and filling a fixed volume in a small weight thereof, a ferrite carrier core material and a ferrite carrier for an electrophotographic developer using the ferrite particle, and the like. In order to achieve the object, there are employed the ferrite particle having a porous structure in the interior thereof and an outer shell structure on the outer periphery thereof, the ferrite carrier core material and the ferrite carrier for an electrophotographic developer using the ferrite particle, and an electrophotographic developer using the ferrite carrier.