CONTINUOUS STEEL CASTING METHOD

The present invention addresses the problem of providing a continuous steel casting method by which it is possible to effectively reduce center segregation with a relatively small rolling load withoutcausing a crack or porosity inside a slab and without requiring a facility having a large rolling capacity and by which existing porosity is eliminated. A continuous steel casting method according tothe present invention involves: enlarging the degree of opening D1 between slab support rolls that are opposite each other with a slab 6 being sandwiched therebetween, toward the downstream side in the casting direction, thereby bulging the thickness T1 of a longitudinal surface of the slab 6, which has a rectangular shape and an unsolidified layer 6a, within the range of 0.1% to 10% of the thickness T2 of the slab in a mold 5; and, when the longitudinal surface S1 of the slab 6 is rolled by a plurality of guide rolls 9, with a slab whose solid phase rate at the thickness center of the slab 6ranges from 0.2 to less th