Provided is a method for producing inorganic fiber including: preparing a spinning raw material liquid which comprises an aluminum source, a calcium source, a silicon source and a spinning auxiliary, in which the content of the spinning auxiliary is, in terms of solid matter, 3 parts by mass or more relative to 100 parts by mass of the total of the aluminum source, the calcium source and the silicon source; spinning the spinning raw material liquid by a sol-gel method to obtain crude inorganic fiber; and firing the crude inorganic fiber to produce inorganic fiber that comprises 35 mass % to 88 mass % of Al2O3, 3 mass % to 45 mass % of CaO and 5 mass % to 40 mass % of SiO2 in which the total of Al2O3, CaO and SiO2 is 97 mass % or more of the entire fiber.