Annealed titanium monoxide TiO1.087 has been studied by the electron diffraction method. A cubic model of the Ti5O5 superstructure (Ti5O5 (Ti9018O9018)) of nonstoichiometric titanium monoxide TixOz has been proposed on the basis of experimental data and representations about the disorder–order transition channel. It has been shown that reflections observed on the electron diffraction pattern are identified in the space group Pm m. The period of the unit cell of the cubic Ti5O5 superstructure is larger than that for the B1 basic disordered structure of TixOz monoxide by a factor of 3. The disorder–order transition channel TixOz (space group Fm m)–Ti5O5 (space group Pm m) includes 75 superstructure vectors of seven stars {k10}, {k7}, {k6(1)}, {k6(2)}, {k4(1)}, {k4(2)}, and {k1}. The distribution functions of Ti and O atoms over the sites of the cubic Ti5O5 (space group Pm m) superstructure have been calculated.