Biomorphic ceramics is a novel inorganic materials with hierarchical structures derived from natural biological structures. This work describes the use of experimental design for optimization of microwave-assisted digestion of biomorphic NiO-ceramic. Beech wood is used as template and it was infiltrated with NiO. XPS and SEM have been used to verify the effectiveness of the synthesis. The effects of different combination of acids in the digestion of this sample have been optimized taking as response the concentration of several metallic ions measured by flame atomic absorption spectrometry (FAAS).