To provide a method for glowing a silicon single crystal where dislocations remained in the central axis portion of a neck part in a necking step can be surely removed when the single crystal with a large diameter and a heavy weight is produced.

In the method for glowing the silicon single crystal by a Czochralski method, the diameter d of the neck part 9 is increased or decreased by forming a diameter-increasing part 9a-1 where the diameter d of the neck part 9 is decreased after increased or diameter-decreasing parts 9b-1 to 9b-4 where the diameter d of the neck part 9 is increased after the diameter d of the neck part 9 is decreased to d1 in a step to form the neck part 9 after a throttled part 8 to reduce the diameter of a seed crystal 7 immersed in a molten liquid by drawing the seed crystal upward is formed. All dislocations including a dislocation on an axis can be efficiently removed when the increase or decrease of the diameter d at the neck part 9 is performed in the final stage of the step to form the neck part 9.