A flame retardant featuring: an inorganic porous fine particle, a phosphazene compound represented by the following average compositional formula (1) ##STR00001## (X is a single bond, CH.sub.2, C(CH.sub.3).sub.2, SO.sub.2, S, 0, or O(CO)O; n is an integer of from 3 to 1000; d and e are numbers with 2d+e=2n), and a resin layer. The phosphazene compound is supported on the inorganic porous fine particle, and the resin layer coats the inorganic porous fine particle with the phosphazene compound supported thereon. The resin layer thermally decomposes to lose weight by 10% at a temperature of from 300.degree. C. to 500.degree. C., as measured by thermogravimetry in the air at a heating rate of 10.degree. C./min.