According to one embodiment, in a method manufacturing a magnetic recording medium which is configured such that a ferromagnetic recording part is formed on a substrate in a desired track pattern or a desired bit pattern, a ferromagnetic film is formed on a substrate, and then a B thin film is formed on a region for isolating the ferromagnetic film between tracks or bits. Subsequently, ions are radiated on the B thin film, thereby increasing a B content of the region of the ferromagnetic film, on which the B thin film has been formed, and nonmagnetizing the region.