A first inclined surface and a second inclined surface are provided on the inside of a mold to constitute a so-called two-step tapered mold. A mold powder is adjusted to have a total content of CaO component and SiO.sub.2 component of not less than 50 wt %, and a content of F component of not more than 11 wt %. The inclination rates of the first and second inclined surfaces are set according to the basicity or solidification temperature of the powder to be used. The pore area of molten steel discharge ports of a dipping nozzle is set to not less than 2500 mm.sup.2 to less than 6400 m.sup.2. The discharge angle of the molten steel discharge ports is set, based on the horizontal, obliquely downward to not less than 10.degree. to not more than 35.degree.. According to such a continuous casting method, solidification delay at angle parts of a bloom can be suppressed.