PROBLEM TO BE SOLVED: To provide a cord stopper capable of suppressing a cap section coming off from a case section.SOLUTION: A cord stopper includes one guide slit 13 penetrating an outer peripheral wall of a case 10, communicating with a hole in an end opening section 12, and extending from a cylindrical end face of the end opening section 12 towards a base end opening section 11 side. A strip-shaped hinge section 20 is connected to the end part on the base end opening section 11 side in the guide slit 13, the hinge section extending from the end towards the end opening section 12 side. The whole of a cap section 30 is fitted into the hole of the end opening section 12 and the guide slit 13, and an outer surface part 33S of the cap section 30, blocking the hole of the end opening section 12, is flush with the cylindrical end face of the end opening section 12.