An information recording medium has a spiral or concentric groove structure along tracks formed on a disk-like substrate wherein each of the tracks is divided into a plurality of recording units, each of the recording units includes a blank portion in a circumferential direction of the groove structure, the groove structure is formed with a wobble in a fixed cycle in a radial direction, and either each length of the recording units is an integer multiple of a cycle of the wobble or the blank portion is so formed that a phase of the wobble formed on the blank portion is continued with a phase of the wobble of the groove structure within another recording unit adjacent to the blank portion.