The double-side polishing apparatus is capable of uniformly polishing a wafer and highly preventing an outer edge of the wafer from being damaged. The apparatus comprises: a lower polishing plate and an upper polishing plate for polishing both sides of the wafer; a carrier having a main body part, in which a through-hole for holding the wafer is formed. Edges of the through-hole in an upper face and a lower face of the carrier are coated with coating layers, which are composed of an abrasion-resistant material and which have a prescribed width and a prescribed thickness. A resin cushion ring, which has a prescribed width and whose thickness is equal to that of the main body part of the carrier, is provided to an inner circumferential face of the thorough-hole. The wafer is held in the resin cushion ring.