An amorphous phase in Nd–Fe–Al system was formed in an extremely wide composition range of 0 to 90 at% Fe and 0 to 93 at% Al by melt spinning. Based on the information on the amorphous formation, ferromagnetic Nd_90−xFe_xAl₁₀ bulk amorphous alloys with high coercive force at room temperature were obtained by a copper mold casting method. The maximum diameter of the cylindrical amorphous samples with a length of 50 mm is about 7 mm for the 20%Fe alloy and about 4 mm for the 30%Fe alloy. Neither glass transition nor supercooled liquid region is observed in the temperature range before crystallization, being different from previous bulk glassy alloys exhibiting a wide supercooled liquid region before crystallization. The onset temperature of crystallization (T_x) and melting temperature (T_m) are measured to be 778 and 863 K, respectively, for the Nd₇₀Fe₂₀Al₁₀ alloy. The resulting reduced ratio of T_x⁄T_m is as high as 0.90 and the temperature interval between T_x and T_m is as small as 85 K. The extremely high T_x⁄T_m and small ΔT_m(=T_m−T_x) values are the reason for the achievement of the large glass-forming ability. The bulk amorphous Nd₇₀Fe₂₀Al₁₀ alloy has a ferromagnetism with the Curie temperature (T_c) of about 600 K which is much higher than the highest T_c (about 480 K) for the Nd–Fe binary amorphous alloy ribbons. The remanence (B_r) and intrinsic coercive force (_iH_c) for the bulk Nd₆₀Fe₃₀Al₁₀ alloy are 0.122 T and 277 kA/m, respectively, in the as-cast state and 0.128 T and 277 kA/m, respectively, in the annealed state for 600 s at 600 K. The B_r and _iH_c decrease to 0.045 T and 265 kA/m, respectively, for the crystallized Nd₆₀Fe₃₀Al₁₀ sample consisting of Nd+Al₂Nd+δ phases and the maximum hard magnetic properties are achieved in the amorphous state. The hard magnetic properties for the bulk amorphous alloys are presumably due to the homogeneous development of ferromagnetic clusters with large random magnetic anisotropy. The finding of the bulk amorphous alloys exhibiting hard magnetic properties at room temperature is promising for the future development as a new type of metallic amorphous permanent magnet.