Abstract. We present structural information obtained on spinel at high temperature (298–2400 K) using in situ XANES at the Mg and Al K-edge. Spinel, ^[4](Al_x,Mg_1-x)^[6](Al_2-x,Mg_x)O₄, with increasing temperature, show a substitution of Mg by Al and Al by Mg in their respective sites. This substitution corresponds to an inversion of the Mg and Al sites. Furthermore, both experiments at the Al and Mg K-edges are in good agreement with XANES calculation made using FDMNES code.