A master information carrier comprises a substrate whose surface has an embossed
pattern corresponding to an information signal. At least a surface of the protruding
portion of the embossed pattern is made of a ferromagnetic material. A method for
writing an information signal into a sheet or disk magnetic record medium with
a ferromagnetic thin film or coating is performed by putting the surface of the
magnetic record medium into contact with the master information carrier so as to
write a magnetized pattern corresponding to the embossed pattern of the master
information carrier into the magnetic record medium.