PURPOSE: To provide a soot blower capable of cleaning multi-stage catalyst layers well by a reduced number of apparatuses, by a method wherein a jet pipe and a blower shaft body crossing the same at right angles are rotated as well as raised to enable the passage thereof through the gap formed in each catalyst layer.

CONSTITUTION: When dust is removed from a catalyst layer, a blower shaft body 1 and a jet pipe 4 are fallen to a predetermined position in the vicinity of the upper surface of a catalyst layer 5 by a shaft body drive apparatus 2 to be changed over to rotation and a valve 11 of an injection medium 12 such as steam is opened. The injection medium 12 is injected while the jet pipe 4 is rotated to uniformly remove dust adhered to the catalyst layer 5. When the dust removal of the catalyst layer 5 is completed, the cleaning of a catalyst layer 10 is started. In this case, the rotation of the jet pipe 4 is stopped and the jet pipe 4 is positioned at the gap 5a formed in the catalyst layer 5 to be lowered to a predetermined position in the vicinity of the catalyst layer 10 along with the blower shaft body 1 to carry out dust removal similarily.