The invention provides an efficient and reliable method for extinguishing fire of a chlorosilane compound, which is a notoriously dangerous inflammable material in respect of the difficulty of extinguishment of fire thereof, by sprinkling a specific porous inert silica based or silica-alumina based powder defined by the content of silica or overall content of silica and alumina as well as various parameters as a powdery material followed by spraying an aqueous solution of sodium chloride, potassium chloride or calcium chloride. The fire extinguishing efficiency can be further enhanced when the sprinkled powder is a blend of the above defined porous powder and a specific silica sand in a specific proportion. When the sprinkled powder is such a binary blend, considerably good results can be obtained even by omitting the step of spraying of the aqueous salt solution.