A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PH 2 O/PH 2 is controlled, a final annealing process where hydrogen in mixed gas atmosphere is controlled to 50 volume% or more, an annealing separator removing process where water-washing is conducted using solution with inhibitor, a smoothing process where mixed gas and temperature are controlled for annealing, and an insulation coating forming process where a baking temperature and a heat treatment temperature are controlled.