This invention provides an inorganic
fiber paper that consists essentially of
inorganic materials and has a basis weight of less than 100 g / m<2> and has been mainly produced by a wet sheet making method. The inorganic
fiber paper comprises inorganic fibers and an inorganic binder as materials, wherein the inorganic fibers have been bound to each other with the inorganic binder. In the inorganic
fiber paper, the content of impurities during wet sheet making is low, the
water resistance and flexibility are good, and satisfactory strength and high
porosity can be realized. The inorganic fiber paper is produced from a material comprising 60 to 97% by
mass of inorganic fibers having an average
fiber diameter of not more than 5 [mu]m and 3 to 40% by
mass of an inorganic binder composed mainly of a silica-based flaky inorganic material that has a hydroxyl group content per specific surface area of not less than 20 [mu]mol / m<2> as measured by a BET method, an average particle
diameter of not more than 2 [mu]m as measured by a
laser scattering method and an
aspect ratio of not less than 10.