Embodiments of the invention provide patterned media in which the center and the direction of the disk can be detected. According to one embodiment, patterned media has a bit pattern including convex portions of a magnetic material on one surface or both surfaces of a nonmagnetic substrate having a central hole. A diffraction grating pattern is formed as an alignment pattern in the inner circumference (or outer circumference) of the patterned media. The diffraction grating pattern is a pattern having a repetitive configuration, and includes a pattern with a repetitive pitch different from that in other portions, or a portion having no pattern, at least one region on a circumference. The diffraction grating pattern is irradiated with detection light and diffracted light is detected, thereby a center and a direction of the disk can be detected.