Grain-oriented electrical steel sheet and method for forming insulating coating

A grain-oriented electrical steel sheet comprising:

• a base steel sheet;
• and
• an insulating coating formed on a surface of the base steel sheet,
• the insulating coating includes
• an intermediate layer formed on a base steel sheet side and containing a crystalline metal phosphate, and
• a tension coating layer formed on a surface side of the insulating coating,
• an average thickness of the intermediate layer is 0.3 to 10.0 μm,
• an average thickness of the insulating coating is 2.0 to 10.0 μm,
• the crystalline metal phosphate of the intermediate layer is one or more of zinc phosphate, manganese phosphate, iron phosphate, and zinc calcium phosphate,
• the tension coating layer contains a metal phosphate and silica, and an amount of the silica in the tension coating layer is 20 to 60 mass %,
• wherein a forsterite-based coating is not formed on the surface of the base steel sheet.