Method for producing grain oriented magnetic steel sheet and grain oriented magnetic steel sheet

A method for manufacturing a grain-oriented electrical steel sheet, comprising the steps of:

• rolling a steel slab containing 0.08 mass percent or less of carbon, 2.0-8.0 mass percent of Si, and 0.005-3.0 mass percent of Mn into a cold-rolled steel sheet;
• subsequently performing decarburizing annealing of the cold-rolled steel sheet if desired;
• subsequently applying an annealing separator to the cold-rolled steel sheet if desired;
• performing secondary-recrystallization annealing of the cold-rolled steel sheet;
• and
• subsequently performing purification annealing of the cold-rolled steel sheet,
• wherein the steel slab contains less than 100 ppm of Al and not more than 50 ppm each of N, S, and Se, the purification annealing is performed at 1050° C. or more, and the partial pressure of hydrogen in the atmosphere is adjusted to 0.4 atm or less in a temperature range above 1170° C. for a purification annealing conducted at a temperature above 1170° C., or 0.8 atm or less in a temperature range of 1050° C. or more for a purification annealing conducted at a temperature of 1170° C. or less.