Grain-oriented electrical steel sheet, annealing separator, and method for manufacturing grain-oriented electrical steel sheet

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to a base steel sheet, an annealing separator utilized for manufacture of grain-oriented electrical steel sheet, and a method for manufacturing grain-oriented electrical steel sheet are proposed. The grain-oriented electrical steel sheet is provided with a base metal steel sheet containing comprising a predetermined chemical composition and a primary coating formed on a surface of the base steel sheet and comprising Mg2SiO4 as a main constituent. The primary coating satisfies the conditions of (1) the number density D3 of the Al concentrated region: 0.020 to 0.180/μm2, (2) (total area S5 of regions which is anchoring oxide layer regions and is also Al concentrated regions)/(total area S3 of Al concentrated regions)≥33%, (3) distance H5 of mean value of length in thickness direction of regions which is anchoring oxide layer regions and is also Al concentrated regions minus H0: 0.4 to 4.0 μm, (4) (total area S1 of anchoring oxide layer regions)/(observed area S0)≥15%.