PURPOSE: To obtain a steel sheet excellent in magnetic properties having uniform grain size free from abnormal grains in the sheet width direction, at the time of manufacturing a grain-oriented silicon steel sheet, by increasing the content of S in a separation agent for annealing to be coated on the surface of a steel sheet after subjected to carburization and primary recrystallization annealing at the edge part of the steel sheet compared to that at the control part.

CONSTITUTION: A silicon-contg. slab is heated, is thereafter subjected to hot rolling, is then subjected to cold rolling for one or two times including process annealing into a final sheet thickness and is thereafter subjected to primary recrystallization annealing served also as decarburization. The surface of the above steel sheet is coated with a separation agent for annealing contg. S compounds and is subjected to secondary recrystallization annealing and purification annealing to manufacture a grain- oriented silicon steel sheet. At this time, the content of S in the separation agent for annealing to be coated on the surface of the steel sheet is increased at the edge part compared to that at the central part by 0.01 to 2.0%. As for the amt. of S to be increased at the edge part, in the case of <0.01%, the improving effect of the grain size is made poor, and on the other hand, in the case of >2.0%, the grain size is excessively coarsened.