To achieve both the lightening of a jig and the improvement of cooling ability, with respect to the spraying of a repairing material to a oven wall of a combustion chamber of a coke oven and the like.

An iron-made end 6A of a cooling hose is inserted from base end 3B of protective cover 3 in such a way that the clearance between spraying lance 2 and protective cover 3 is plugged. The other end which is not shown in the figure is connected to the delivery side of an air pump for feeding cooling air. Cooling air fed through cooling hose 6 is discharged from the end 6A and is fed to the clearance between spraying lance 2 and protective cover 3. By continuous feeding to the clearance, the cooling air is then discharged from an end 3A of protective cover 3 to the outside. The continuous feeding of cooling air as stated above results in accelerating the cooling of spraying lance 2 and in reducing the possibility of its loss by scorching.