A method of growing a silicon single crystal by which a silicon single crystal having an oxygen concentration of 12×10 17 -18×10 17 atoms/cm 3 as determined through a measurement in accordance with ASTM-F121 1979 is grown by the Czochralski method. The atmospheric gas in which the single crystal is grown is a mixed gas comprising an inert gas and the gas of a hydrogen-atom-containing substance. The temperature of the silicon single crystal being grown is controlled so that the ratio of the axial-direction temperature gradient in the crystal core Gc in the range of from the melting point to 1,350°C to the axial-direction temperature gradient in a crystal periphery part Ge in the range of from the melting point to 1,350°C, Gc/Ge, is 1.1-1.4 and that the axial-direction temperature gradient in the crystal core Gc is 3.0-3.5 °C/mm.