PURPOSE: To simplify by individually mounting a first lance having a sample- collecting ladle detachable at its end and a second lance for holding a temperature measuring holder which can mount a temperature measuring probe at its end, and fixing pushing and pulling means for moving the second lance to the first lance.

CONSTITUTION: A first lance 1 is fixed to an elevation truck 2 which is vertically moved along an elevation guide rail 4 via guide rollers 3 through a mounting bracket 17, and the truck 2 is vertically moved by an elevator 7 via a chain 5 wound on a plurality of sprockets 6. A sample collecting ladle 10 is detachably mounted at an end of the lance 1 through a ladle mounting fitting 9. A pneumatic cylinder 14 of pushing and pulling means is mounted at the lance 1 through a bracket 18, and a second lance 11 is connected thereto. A temperature measuring holder 12 is held ad the end of the lance 11, and a temperature measuring probe 13 is mounted thereat. The lance 11 is guided along a guide rail 16 via rollers 15.