The density of the magnetic head protective layer is set to be higher than the density of a magnetic disc medium protective layer. The plasma processor is provided with an electric potential control DC power supply 33 to control the electric potential of this focus ring 9, and so constituted that the lower electrode 4 is supplied with a DC voltage of, e. The noble metal nanoclusters are preferably encapsulated by a dendrimer or a peptide. The inner portion may comprise an amount of rigidity within a range from about 1\xd710\u22124 Pa*m3 to about 5\xd710\u22124 Pa*m3 so as to deflect and conform at least partially to the ablated cornea and smooth an inner portion of the ablation with an amount of pressure when deflected.