PURPOSE: To safely and quickly execute attachment/detachment of a small tuyere by fitting an exchanging jig to the small tuyere, supporting pivotally the dead wt. of the small tuyere with a supporting jig and energizing the exchanging jig with hydraulic pressure.

CONSTITUTION: In the exchange of the small tuyere 1 in a blast furnace, a yoke 5 is pressed with a hydraulic cylinder 9 fixed to a fixed base 4 and the exchanging jig 6 fitted to end part of the yoke 5, is fitted to a pull-out piece 3 in the same tuyere 1 with pins 7. A supporting piece 11 in the supporting jig 8 fixed to the fixed base 4 is made approach to the upper part of inner face in the small tuyere 1. The exchanging jig 6 pulls the small tuyere 1 by the pressure of the yoke 5 and the supporting piece 11 in the supporting jig 8 abuts on the upper part of inner face in the small tuyere 1 to support the dead wt. of small tuyere 1. After that, the small tuyere 1 is laid on a carriage.