Alumina and alumina-based compounds are amongst the most used ceramic materials, due to their high chemical and thermal stability, their low density and good mechanical properties. For most of the technological applications, a controlled chemical composition and a fine microstructure are required. The SPS sintering and the study of the structural, electronic and optical properties of MgAl2O4 ceramics with a spinel structure and optically transparent are envisaged in the field of optics resistant to ionizing radiation. Nanostructured MgAl2O4 ceramics will result from the sintering, by SPS method (Spark Plasma Sintering), of nanometric MgAl2O4 commercial powder. In our team, we have recently shown the possibility of nanostructuring the MgAl2O4 ceramic using a commercial powder with grains of 70 nm leading to transparent ceramics with an average grain size of 135 nm and an optical transparency in the visible range of 84%. Here, we will present our current work aiming to decrease the size of grains below 100 nm we will present our current work aiming at decreasing the size of the grains below 100 nm by using as precursors MgAl2O4 nanopowders that we synthesize following two synthesis methods developed in the laboratory. The first one is in polyol medium to obtain particles of about 3 nm and the second consists in the growth of an ultra-porous alumina (UPAs) precursor according to an original process set up and patented about fifteen years ago by members of the laboratory MINOS-LSPM. The UPAs synthesized using this technique will be added to metallic salts by impregnation followed by heat treatment to obtain MgAl2O4 nanoparticles. These different routes should lead to obtaining a mixture of precursors with great chemical homogeneity and controlled size.