A substrate polishing apparatus for polishing a polishing surface of a substrate has a film thickness monitoring device for monitoring a state of a film thickness of a thin film on the polishing surface of the substrate during polishing. The apparatus includes a table, a polishing member fixed on a surface of the table, a substrate support member for pressing the substrate onto the polishing member, an optical system composed of an optical fiber for irradiating the polishing surface of the substrate with a light of irradiation and an optical fiber for receiving a reflected light reflected on the polishing surface of the substrate, an analysis-processing system for processing an analysis of the reflected light received with the optical system, and the film-thickness monitoring device. The table is provided with a liquid-feeding opening for feeding a translucent liquid into a through-hole disposed in the polishing member.
This is application is a divisional of U.S. patent application Ser. No. 11/806,445, filed May 31, 2007 now U.S. Pat. No. 7,510,460, which is a divisional of U.S. patent application Ser. No. 11/169,797, filed Jun. 30, 2005, now U.S. Pat. No. 7,241,202, issued Jul. 10, 2007, which is a divisional of U.S. patent application Ser. No. 10/854,250, filed May 27, 2004, now U.S. Pat. No. 6,942,543, issued Sep. 13, 2005, which is a divisional of U.S. patent application Ser. No. 10/329,424, filed Dec. 27, 2002, now U.S. Pat. No. 6,758,723, issued Jul. 6, 2004.
