Abstract: In a CMP conditioner in which abrasive grains are fixed to a protrusion protruded from an upper surface of a base, the abrasive grains are stably fixed to prevent a scratch from being generated due to detachment of the abrasive grains and a space for holding a polishing fluid is surely ensured between a protrusion section of the protrusion surrounding the abrasive grains and the pad upon dressing. In the CMP conditioner in which protrusions are protruded from an upper surface of a base which rotates around an axis line and a plurality of abrasive grains is fixed to the protrusions, the abrasive grains are fixed such that the abrasive grains are not protruded from a virtual extending surface which extends from the peripheries of protrusion sections, which face protrusion directions of the protrusions, along the axis line.