To form a magnetic thin-film layer without causing a nonmagnetic base to deform, by forming gentle slopes of both end parts of the magnetic thin-film layer on the nonmagnetic base.

This device is equipped with a conveying means 6 which conveys the nonmagnetic base 2, vaporizing means 9 and 10 which are arranged below where the nonmagnetic base 2 is conveyed and heat and vaporize a metal magnetic material 3, a cylindrical guide member 8 which is arranged above the vaporizing means 9 and sends the nonmagnetic base 2 while cooling it so as to vapor-deposit the heat and vaporized metal magnetic material 3, and restricting means 11 and 12 which restrict the vapor-deposition area of the heated and vaporized metal magnetic material 3 about the nonmagnetic base 2. The restricting means 12 is varied in opening width for restricting vapor- deposition area in the travel direction of the nonmagnetic base 2 traveling on the circumferential surface of a guide member.