A method of manufacturing a grain-oriented electrical steel sheet comprising: heating a silicon steel slab at 1280°C or below, the silicon steel slab containing, in % by mass, Si: 0.8% to 7%, and acid-soluble Al: 0.01% to 0.065%, with a C content of 0.085% or less, a N content of 0.012% or less, a Mn content of 1% or less, and a S equivalent Seq., defined by "Seq.= +0.406×[Se]" where being S content (%) and [Se] being Se content (%), of 0.015% or less, and optionally at least one selected from the group consisting of Cr: 0.3% or less, P: 0.5% or less, Sn: 0.3% or less, Sb: 0.3% or less, Ni: 1% or less, Bi: 0.01% or less, B: 0.01% or less, Ti: 0.01% or less, Te: 0.01% or less and Cu: 0.4% or less by mass, and the balance of Fe and unavoidable impurities; hot rolling the heated silicon steel slab so as to obtain a hot-rolled steel strip; annealing the hot-rolled steel strip so as to obtain an annealed steel strip; cold rolling the annealed steel strip so as to obtain a cold-rolled steel strip; decarburization annealing the cold-rolled steel strip so as to obtain a decarburization-annealed steel strip in which primary recrystallization is caused; coating an annealing separating agent on the decarburization-annealed steel strip; and finish annealing the decarburization-annealed steel strip so as to cause secondary recrystallization, wherein the method further comprises performing a nitriding treatment in which a N content of the decarburization-annealed steel strip is increased between start of the decarburization annealing and occurrence of the secondary recrystallization in the finish annealing, the hot rolling the heated silicon steel slab comprises: finish rolling with a finish temperature of 950°C or below; and starting cooling within 2 seconds after completion of the finish rolling, and coiling at 700°C or below, a heating rate of the hot-rolled steel strip within the temperature range from 800°C to 1000°C in the annealing the hot-rolled steel strip is 5°C/sec or above, and characterized in that a cooling rate over a duration from the completion of the finish rolling up to a start of the coiling is 13°C/sec to 14°C/sec. heating a silicon steel slab at 1280°C or below, the silicon steel slab containing, in % by mass, Si: 0.8% to 7%, and acid-soluble Al: 0.01% to 0.065%, with a C content of 0.085% or less, a N content of 0.012% or less, a Mn content of 1% or less, and a S equivalent Seq., defined by "Seq.= +0.406×[Se]" where being S content (%) and [Se] being Se content (%), of 0.015% or less, and optionally at least one selected from the group consisting of Cr: 0.3% or less, P: 0.5% or less, Sn: 0.3% or less, Sb: 0.3% or less, Ni: 1% or less, Bi: 0.01% or less, B: 0.01% or less, Ti: 0.01% or less, Te: 0.01% or less and Cu: 0.4% or less by mass, and the balance of Fe and unavoidable impurities; hot rolling the heated silicon steel slab so as to obtain a hot-rolled steel strip; annealing the hot-rolled steel strip so as to obtain an annealed steel strip; cold rolling the annealed steel strip so as to obtain a cold-rolled steel strip; decarburization annealing the cold-rolled steel strip so as to obtain a decarburization-annealed steel strip in which primary recrystallization is caused; coating an annealing separating agent on the decarburization-annealed steel strip; and finish annealing the decarburization-annealed steel strip so as to cause secondary recrystallization, wherein the method further comprises performing a nitriding treatment in which a N content of the decarburization-annealed steel strip is increased between start of the decarburization annealing and occurrence of the secondary recrystallization in the finish annealing, the hot rolling the heated silicon steel slab comprises: finish rolling with a finish temperature of 950°C or below; and starting cooling within 2 seconds after completion of the finish rolling, and coiling at 700°C or below, a heating rate of the hot-rolled steel strip within the temperature range from 800°C to 1000°C in the annealing the hot-rolled steel strip is 5°C/sec or above, and characterized in that a cooling rate over a duration from the completion of the finish rolling up to a start of the coiling is 13°C/sec to 14°C/sec. finish rolling with a finish temperature of 950°C or below; and starting cooling within 2 seconds after completion of the finish rolling, and coiling at 700°C or below, a heating rate of the hot-rolled steel strip within the temperature range from 800°C to 1000°C in the annealing the hot-rolled steel strip is 5°C/sec or above, and characterized in that a cooling rate over a duration from the completion of the finish rolling up to a start of the coiling is 13°C/sec to 14°C/sec.