This disclosure is directed to a chemical mechanical polisher and a polishing pad component thereof. The chemical mechanical polisher comprises a polishing platen having a flat surface, and the polishing platen comprises: an electromagnet disposed under the flat surface and configured to fix a polishing pad base on the flat surface; and a switch configured to control the power-on and power-off of the electromagnet. The polishing pad component comprises a polishing pad base, and the polishing pad base is formed of a ferromagnetic material. The chemical mechanical polisher of this disclosure and the polishing pad component thereof can make polishing pad replacement easy, and can also save polishing pads and thus reduce the consumable cost of the chemical mechanical polishing.