Abstract: A method for producing an inorganic porous shaped product comprising the steps of mixing silica dust with water, shaping the mixture, drying the shaped product to adjust the water content thereof to 1 to 10 weight percent and thereafter firing the shaped product at a temperature of 1,000.degree. to 1,450.degree. C, said silica dust being:(i) a by-product from the process of producing ferrosilicon by electrothermal metallurgy, and(ii) 0.1 to 1.0 .mu. in particle size, 10 to 50 m.sup.2 /g in specific surface area and about 0.1 to about 0.3 g/cm.sup.3 in bulk density,And comprising 85 to 98 weight percent of amorphous silica, 0.2 to 2.0 weight percent of FeO, 0.2 to 5.0 weight percent of Al.sub.2 O.sub.3, 0.5 to 2.0 weight percent of MnO, 0 to 0.1 weight percent of CaO, 0.5 to 5.0 weight percent of MgO and 0.1 to 1.5 weight percent of others.