PROBLEM TO BE SOLVED: To provide an iron oxide porous body which has sufficiently high purifying performance with respect to reactive molecules such as a volatile organic compound (for example, acetaldehyde) contained in the air when used as an air purifying material.SOLUTION: The iron oxide porous body comprises an agglomerate in which primary particles of iron oxide agglomerate, wherein the average particle diameter of the primary particles is 2-8 nm and the median pore diameter of pores of the agglomerate is 2-10 nm. The iron oxide porous body has a two-line ferrihydride phase which shows two peaks comprising one peak derived from the (110) plane of a crystal and the other peak derived from the (300) plane of the crystal in an X-ray diffraction pattern, and the content ratio of the two-line ferrihydride phase to the whole crystal phase of the iron oxide is ≥40 mass%. The total amount of impurities comprising oxides of silicon, aluminum, tin, zinc and titanium is ≤0.1 mass%.
