PURPOSE: To obtain the titled steel plate having excellent secondary working brittleness resistance by subjecting the steel in which C, Mn, S, N, Al, Zr and Ti are specified to rolling and annealing treatments under prescribed conditions, thereby using the interstitial free steel contg. extra low carbon.

CONSTITUTION: The steel contg., by weight, ≤0.005% C, 0.001W0.5% Mn, ≤0.02% Si, ≤0.007% N, ≤0.1% acid soluble Al and to which Zr and Ti are compositely added in the appropriate range is refined. Said steel is soaked at ≥1,000°C and is hot rolled at the finish temp. of Al transformation point or above. The steel is then wound at ≤720°C and is cold rolled at 60W95% pressurizing ratio. Said steel is furthermore heated to the recrystallization temp. W AC3 transformation point and is continuously annealed.