A slab with a predetermined composition is heated at 1280° C. to 1390° C. to make a substance functioning as an inhibitor to be solid-solved (step S1). Next, the slab is hot-rolled to obtain a steel strip (step S2). The steel strip is annealed to form a primary inhibitor in the steel strip (step S3). Next, the steel strip is cold-rolled once or more (step S4). Next, the steel strip is annealed to perform decarburization and to cause primary recrystallization (step S5). Next, nitriding treatment is performed on the steel strip in a mixed gas of hydrogen, nitrogen and ammonia under a state where the steel strip runs, to form a secondary inhibitor in the steel strip (step S6). Next, the steel strip is annealed to induce secondary recrystallization (step S7).