On an information recording medium, a data track pattern and a servo pattern composed of a concave/convex pattern including a plurality of convex parts are formed on at least one surface of a substrate and respective concave parts in the concave/convex pattern are filled with non-magnetic material. In the concave/convex pattern that constructs the servo pattern, a unit convex part length along a direction of rotation of the substrate and a unit concave part length along the direction of rotation are set so that the ratio of the unit convex part length to the unit concave part length decreases from an inner periphery to an outer periphery of the information recording medium.