A forsterite careful blur accepting a acceptable adherence acreage to a grain-oriented silicon animate area with a aerial alluring consecration is composed of forsterite grains accepting a beggarly atom admeasurement of not added than 0.7 .mu.m. The forsterite careful blur is formed by annealing a braid of a algid formed silicon animate band accepting a final barometer in an annealing boiler beneath an apathetic gas atmosphere at a connected temperature befitting date of 800.degree.-920.degree. C so as to absolutely advance accessory recrystallized grains and again beneath hydrogen gas atmosphere at a temperature ascent date up to 1,150.degree.-1,250.degree. C and a connected temperature befitting date of 1,150.degree.-1,250.degree. C during the final annealing, provided that an boilerplate dew point of the atmosphere is aural a ambit of -20.degree. C to +20.degree. C in the temperature ascent date up to 1,150.degree.-1,250.degree. C and not added than +10.degree. C in the connected temperature befitting date of 1,150.degree.-1,250.degree. C.