Hematite (alpha-Fe2O3) is an antiferromagnetic material with a very low spin damping and high Neel temperature. The temperature dependence of the antiferromagnetic resonance in a bulk single crystal of hematite was characterized from room temperature up to the Neel temperature in the frequency range of 0.19-0.5 THz. From these data, the Neel temperature was estimated as 966 K. (C0 2022 Author(s).