This invention permits formation of a magnetic coating excelling in the degree of orientation in spite of a decrease in the thickness thereof and ensures impartation of a high degree of packing and high durability to the magnetic layer of a small thickness because of the infallible presence of a backcoat layer in an undried state (particularly a wet state) while the magnetic layer is in an undried state (particularly a wet state). It also allows efficient formation of a backcoat layer which used to impose a heavy load on the conventional process of manufacture. Preferably, this invention has the calendering work performed in the in-line system such that the surface quality of the magnetic layer may be exalted by improving the operational efficiency of the calendering step and, as a result, the loss of the applied layer of the paint which used to occur during the course of the calendering step in the conventional separate line may be decreased.