A polishing composition contains a compound represented by the general formula (1) below and abrasive grains. In the general formula (1), X represents a residue of polyether polyol (having a polyether chain containing an oxyethylene group in an amount of 20 to 90% by mass) derived from a compound having an active hydrogen atom and an alkylene oxide; m represents an integer of 2 to 8, which is equal to the number of hydroxy groups contained in a single polyether polyol molecule; Y and Z represent a lower alcohol residue to which ethylene oxide or propylene oxide is added by addition polymerization, an alkyl group or an alkylene group, respectively; and n is an integer of 3 or more. ##STR00001##