A main shaft is reversed from an initial stop time point, after a loom is stopped due to a cause of stoppage that is an occurrence of a weft insertion defect or due to causes of stoppage that are an occurrence of a warp breakage and an occurrence of a weft insertion defect accompanied with the warp breakage, while the leveling function of a warp shedding device is disabled to bring the loom into a stand-by state in a weaving cycle in which the cause or causes of stoppage have occurred. The main shaft is reversed in response to an operator operating a reverse button while the loom is in the stand-by state to bring the loom into a pick-found state, in which the defective weft pick is pickfound, and the operator is allowed to remove the defective weft pick in the pick-found state. The main shaft is reversed in response to the operator operating a button after a removal of the defective weft pick while the leveling function of the warp shedding device is enabled to bring the warps into a leveled state.