An inorganic fiber structure comprising inorganic nanofibers having an average fiber diameter of 3 μm or less, in which an entirety including the inside thereof is adhered with an inorganic adhesive, and the porosity thereof is 90% or more, is disclosed. Furthermore, a process for producing an inorganic fiber structure is disclosed, which includes (i) a step of spinning inorganic fibers by an electrospinning method, from a spinning inorganic sol solution containing a compound mainly composed of an inorganic component; (ii) a step of forming an inorganic fiber aggregate by irradiating the inorganic fibers with ions having a polarity opposite to that of the inorganic fibers to accumulate the inorganic fibers; and (iii) a step of forming an inorganic fiber structure adhering to the inorganic fiber aggregate with an inorganic adhesive in an entirety including the inside thereof, in which an adhering inorganic sol solution containing a compound mainly composed of an inorganic component is imparted to an entirety including the inside of the inorganic fiber aggregate, and an excess adhering inorganic sol solution is removed by gas-through.