PURPOSE: To control the gas from a melt and to suppress an increase in carbon concn. and defects without changing a heat balance by disposing a structure consisting of a specific material in order to control gaseous flow above the melt with the apparatus for production of the silicon single crystal by a Czochralski method.

CONSTITUTION: The apparatus 1 for the silicon single crystal consists of a chamber 2, a heat insulating material 3, a heater 4, a protective body 5 and a quartz crucible 6 and a seed crystal is mounted to a pulling up shaft 8. The seed crystal is pulled up while the crystal is immersed into the melt 7, by which the columnar silicon single crystal 9 is produced. The structure (e.g.: made of quartz glass) 11 for controlling the flow of the gaseous SiO from the melt 7 is constituted of a cylindrical part 12 and an inverted circular conical part 13 and is imposed on a cylindrical support 14. An inert gas is introduced from an introducing path 10, is introduced to a lower aperture through the circumference of the silicon single crystal 9 in the cylindrical part 12 of the structure 11 according to an arrow and is further introduced diagonally upward from the surface of the melt 7 through the inverted circular conical part 13. As a result, the gaseous SiO is led radially outward and is prevented from sticking and falling.