The concept of a bio-nanobattery is based on ferritin, an iron storage protein that naturally exists in most biological systems. Biomineralization allows ferritins to reconstitute iron core with various metallic cores. When the ferritin half cells are integrated into a complete battery system, the fabrication of well-organized ferritin arrays is necessary and very important to enhance the overall battery performance, improving the battery power density, the power discharge rate, the compactness of battery size, etc. In this work, a spin self-assembly (SA) method was used for producing a thin-film array structure of ferritins. The spin SA deposition was repeated until two bilayers of cationized and native ferritins or 4 alternating ferritin layers were achieved. High-resolution field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and variable angle spectroscopic ellipsometry (VASE) were used to characterize the multilayered ferritin arrays. The thickness of ferritin multilayer increased linearly as the spin SA deposition was repeated. The spin SA deposition method produced well-organized, uniform, and flat ferritin layers in a much shorter period of time, compared with Langmuir-Blodgett or dipping deposition methods. Such enhancement can be attributed to a strong electrostatic attraction that holds the ferritin layer on the substrate during the spin-coating process while hydrodynamic drag and centrifugal forces remove loosely-bound ferritins.