A method of continuously casting molten steel to produce high surface quality slab by preventing depressions and cracking. The steel is high Al steel having an Al content of 0.1% or more. High-Al molten steel is continuously cast using mold powder containing T—CaO (T—CaO presumes total Ca converted to CaO): 35 to 55%, SiO2: 10 to 30%, Al2O3: 4.0% or less (excluding 0%), MgO: 0.2 to 1.0%, Li2O: 7 to 13%, F: 7 to 13%, C: 10.5 to 14%, and inevitable impurities; and satisfying: 1.6≦[T—CaO]/[SiO2]≦5 and 0.2≦[Li2O]/[SiO2]≦1.1. The method is performed by controlling the molten steel surface level fluctuation speed in the mold; the pouring angle of the molten steel in the width direction of the mold; the stroke in the amplitude; and the negative strip time tN as defined.