The present invention provides a magnetic disk in a discrete track medium and a patterned medium, which prevents the loss of the magnetically recorded data when a head of a magnetic disk device contacts the magnetic disk, and a manufacturing method thereof. A magnetic disk has a protrusion as a non-magnetic member formed on a disk surface to prevent a head from being in contact with a recording section. When the protrusion formed in a disk substrate collides against the head, the protrusion 7 does not collapse, and accordingly, the recording layer is not damaged. Alternatively, concave and convex portions are formed on the substrate surface to use the convex portion as the protrusion.