A process for producing a single crystal of semiconductor material, in which fractions of a melt, are kept in liquid form by a pulling coil, solidify on a seed crystal to form the growing single crystal, and granules are melted in order to maintain the growth of the single crystal. The melting granules are passed to the melt after a delay. There is also an apparatus which Is suitable for carrying out the process and has a device which delays mixing of the molten granules and of the melt.