A velocity of Ar gas flow passing through between a lower end of a cylindrical body and a thermal shielding body is influenced by arrangement of a pulling path of single crystal silicon, a cylindrical body, and a thermal shielding body. Accordingly, the velocity of the Ar gas flow passing through between a lower end of the cylindrical body and the thermal shielding body is controlled by adjusting a relative position of the pulling path of the single crystal silicon, the cylindrical body, and the thermal shielding body. As described above, dust falling off to silicon melt can be reduced, thereby preventing deterioration in quality of the single crystal silicon.