We performed nitrogen atomic‐layer doping into GaAs grown by molecular beam epitaxy using nitrogen molecules (N2) cracked by a hot tungsten filament. While uniformly nitrogen‐doped GaAs layers show relatively weak nitrogen‐related photoluminescence lines, nitrogen atomic‐layer‐doped GaAs layers show a series of sharp and strong photoluminescence lines. The dominant photoluminescence line was observed at 1.4437 eV, where an exciton bound to the nitrogen isotropic traps has the highest binding energy. ©1995 American Institute of Physics.