Abstract: A process of growing crystals in which the uniformity of the oxygen concentration is desirable. In the process, the upper part of the material in the crucible is heated to form a molten layer, and a solid layer is formed at its lower part, then a seed crystal is made to contact the surface of the molten layer, and pulled up to grow a crystal, while characteristically a magnetic field is applied to the molten layer. This method produces single crystals with a uniform distribution of oxygen concentration. Furthermore, this method produces single crystals at low cost and with a high productivity.