PURPOSE: To simultaneously satisfy discoloration resistance and good workability by subjecting steel having specific components to finish rolling, cold rolling, annealing and nitriding treatments, then to a heat treatment under specific conditions.

CONSTITUTION: The components of the steel sheet are composed to contain, by weight, ≤0.05% C, ≤0.005% N, ≤1.5% Mn, ≤0.5% Si, ≤0.1% P, ≤0.05% Al and B under condition of 0.7<B/N<1.5 and the balance Fe with inevitable impurities. This steel is subjected to finish rolling at Ar3 or above and is then coiled up at ≥500 to ≤780°C. The steel sheet is then subjected to recrystallization annealing after cold rolling, then to a nitriding treatment at ≥20 to ≤500 in the product of the concn. (%) of NH3 and residence time (sec) in a nitriding atmosphere kept at ≥600 to ≤800°C. The steel sheet is subjected to hot dip Al coating, then to the heat treatment for ≥2 to ≤10 hours at ≥300 to ≤450°C. As a result, the hot dip aluminum coated steel sheet which is suppressed in the deterioration of merchandise value by thermal discoloration as far as possible is produced.