Patent ID: 7988537

Claim:
A substrate holding apparatus for holding and pressing a substrate to be polished against a polishing surface, said substrate holding apparatus comprising: a vertically movable member; an elastic member connected to said vertically movable member; and a retainer ring arranged around said elastic member, wherein said vertically movable member is vertically movable relative to said retainer ring, said elastic member including (i) a contact portion to be brought into contact with the substrate, (ii) an inner circumferential wall extending upwardly from said contact portion and being connected to said vertically movable member, and (iii) an outer circumferential wall extending upwardly from said contact portion and being connected to said vertically movable member, said outer circumferential wall being concentric with said inner circumferential wall, each of said inner circumferential wall and said outer circumferential wall having a folded-back structure including an inwardly folded wall and an outwardly folded wall, wherein each folded-back structure is positioned so as to be extendible and contractible vertically with said contact portion being kept in contact with the substrate, and such that said folded-back structure of said inner circumferential wall and said folded-back structure of said outer circumferential wall extend and contract vertically together with each other.