PURPOSE: To obtain the accurate result of the components of molten steel within a short time by rapidly and certainly forming the surface of molten steel having no slag and an oxide film when the components of molten steel are analyzed.

CONSTITUTION: The quartz cylinder 14 attached to the leading end part of a purge pipe 11 is immersed in sampled molten steel S and molten steel is allowed to flow in the quartz cylinder 14 by opening the lid 16 provided on the quartz cylinder 14. Thereafter, the surface of molten steel is irradiated with laser beam and the components of molten steel S are analyzed by laser emission spectral analysis.