Ferrite spinel’s MFe2O4 (M = Co, Fe, Zn, Mn, and Cu) nanoparticles were produced by a co-precipitation method. The X-ray diffraction (XRD) analysis was used to verify phase purity, crystal structure, and average crystallite size of MFe2O4 nanoparticles. All samples have not any phase impurity, which has a spinel structure with crystallite sizes between 7 and 29 nm. (312)