Polishing pad, polishing apparatus, method for producing polishing pad and method for producing polished object

A polishing apparatus comprising:

• a polishing pad comprising a resin comprising a void,
• wherein the resin includes a first resin and a second resin, a hardness of the first resin being higher than a hardness of the second resin,
• wherein a surface layer comprising a polishing surface of the polishing pad comprises the first resin,
• wherein a region of the polishing pad comprises the second resin, and
• wherein, when a value of a circle-equivalent diameter of the void in the polishing surface is defined as a void diameter of a front surface, and a value of a circle-equivalent diameter of the void in a surface of the polishing pad opposite to the polishing surface is defined as a void diameter of a back surface, a difference between the void diameter of the front surface and the void diameter of the back surface is within 15%;
• a fixing part for fixing the polishing pad;
• and
• a holding part for holding an object.

A method for producing a polishing pad, the method comprising:

• preparing a resin having a void;
• and
• subjecting a surface layer forming one surface of the resin to curing treatment to provide the resin with a first resin and a second resin, a hardness of the first resin being higher than a hardness of the second resin,
• wherein, when a circle-equivalent diameter of the void in the cured surface is defined as a void diameter of a front surface, and a circle-equivalent diameter of the void in a surface of the resin opposite to the cured surface is defined as a void diameter of a back surface, a difference between the void diameter of the front surface and the void diameter of the back surface is within 15%.