A double-wall crucible is disclosed which is constructed by coaxially disposing a cylindrical partition wall in an outer crucible for holding a molten mass of silicon as a raw material and operated by heating the outer crucible and meanwhile supplying the raw material silicon to the gap between the outer crucible and the cylindrical partition wall and introducing the consequently produced molten mass of silicon to the interior of the cylindrical partition wall through a passage below the level of the molten mass of silicon interconnecting the outer crucible and the inner side of the cylindrical partition wall and meanwhile pulling a single crystal bar from the molten mass of silicon in the cylindrical partition wall. In this double-wall crucible, at least the cylindrical partition wall is formed of quartz glass having a hydroxyl group (OH group) content of not more than 30 ppm. <IMAGE>
