Magnetic domains of a press‐sintered SmCo5magnet with a high intrinsic coercivity (IHc= 12 700 Oe) and energy product [(BH)max= 18.0 MGOe] were observed in the demagnetized state by the powder pattern technique. The domains on the surfaces parallel and perpendicular to the alignment direction and at grain boundaries are shown in detail. The domain structures observed are of the same type as those for thick crystals with high uniaxial anisotropy, such as MnBi and BaFe12O19.