We report on neutron scattering experiments on the intermediate valence compound TmSe. Its properties are discussed assuming the existence of 50 % Tm3+ and 50 % Tm2+. At high temperatures (T > 120 K) both states are incoherently mixed. At low temperatures (T < 75 K) both states seem to separate leaving the Tm2+ ions in a magnetic ground state while the Tm3+ ions develop a non magnetic singlet ground state