When copying servo information from an electro-magnetic field copy master
to a vertical storage medium, the magnetization direction of the vertical
storage medium is made to the direction the reverse of an external
electro-magnetic field applied to the vertical storage medium and the
electro-magnetic field copymaster, the vertical storage medium is closely
touched on the electromagnetic field copy master provided with a
substrate which has concavity/convexity corresponding to the servo
information and at least the convex part of which of the
concavity/convexity is made of a softly magnetic material and a conductor
installed in the concave part of the substrate and an external
electro-magnetic field stronger than the coercive field strength of the
vertical storage medium is instantaneously applied to the vertical
storage medium and the electromagnetic field copy master.